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Dear Labby: Questions For Our Ballistics Lab


Our ballistics lab fields many questions a day from our customers. Here are some of the questions from last week:

Kaizen Handloading

Dear Labby,
What do you think is the most common piece of equipment that causes dangerous problems in handloading? My friend and I have a bet. He picked primer pickup tubes and I said it was the powder thrower, well, because it throws powder. I know a guy who got confused about what powder was in their thrower and blew a gun. Who do you think is right?  Brian M. Wolf Point, MT

Well, I guess between these two options, I’m on your side. Primer pickup tubes will detonate and fly off like rockets. There was a hole in the ceiling from one at the first gun manufacturer I worked for. A primer had gone off in a Rock Chucker and sent the primer pickup tube through the false ceiling. Nobody was hurt, though.

Always check to insure that your powder hopper is empty. Small amounts of powder left over from the last reloading session can lead to catastrophic failures.

At that same company a couple of years later, a .17 Mach IV came in with its lugs sheared off and the bolt partially open. Only debris from the lugs in the raceways kept the bolt in the rifle. That was caused by not emptying the powder thrower completely. It had fast pistol powder left over in the bottom of the hopper that he hadn’t noticed. Even though he put the right powder in the hopper, the first powder throw was the pistol powder from the bottom of the hopper. So, given what you asked, mistakes with powder are consistently more dangerous than mistakes with primers.

The RCBS Auto Priming Tool is well designed, tipping the primer tube away from the case while it is primed.

Now, if I could pick one common tool on the loaders bench that I would remove to make handloading safer, I would get rid of loading trays. The loading trays themselves aren’t a bad thing, in fact they are pretty useful. Where people run afoul of them is by using bad loading techniques.

It is common practice to carefully load each case with power, and then carefully place each charged case back into the load tray. Once all of the cases have been charged, they are carefully picked up again, making sure not to disturb the other cases, and a bullet is then inserted into the cartridge. I’m emphasizing carefully here, because the loader is trying not to spill powder in either the case being manipulated or from the other, already filled, cases. I have accidently jostled my loading trays many times and spilled powder out of cases. The result is that they all need to be dumped and the process begun again. Once, in a feat of clumsiness, I managed to dump drop a complete tray of .45 ACP charged cases. A lot of careful manipulation had to be repeated after that mistake to make up for the lost work.

Manipulating an entire loading tray to charge cases is a clumsy and potentially dangerous chore.

Where people really get into trouble is by trying to charge cases in the trays by moving the whole tray under the thrower. It is awkward (and again prone to being spilled or dropped) but more importantly it has the potential for unfilled or double filled cases. Careful inspection of each case is imperative if this operation is used.

A better system is to charge each case individually, then inspect the charge to see that it looks correct, and then to seat the bullet. The bullet can then be set into the loading tray for later inspection and storage. I usually have box of prepped and primed brass on the left side of my press, my powder thrower preset and a box of bullets within reach. Each case is manipulated once, from the start of the charging process until the finished cartridge is set aside. Think of it as Kaizen handloading. All of the awkward extra steps, the potential for a double charged case and concern for spilled powder has been removed. The process is now: charge, inspect, seat the bullet, inspect, and set aside for storage. Try it, the motions will become rote and you will make safer loads more quickly.

Instead of charging all the cases and then moving on to seating bullets as a separate step, walk each case individually through the entire loading process. Charge the case.


Seat the bullet.

Measuring the Chamber Vs. Measuring the Magazine Length

I’ve just finished measuring the O.A.L. of several different bullets in my Remington Model 700 300 Win.Mag. with a stainless barrel using the Hornady O.A.L. gauge. All of the cartridges measured quite a bit over the 3.340″ that is the maximum length for this cartridge. They measured from a low of 3.484″(Sierra 2160 180gr) to a high of 3.655″ (Nosler Partition 180gr) a total of 8 different bullets and 4 different weights. I’ve never loaded anything over 3.340″ . Are all 300 Win. Mag”s this much larger in the chamber and throat section of the gun. With the short neck section of the case I would not feel safe loading anything over 3.340″. I know when I measured my 30-06 none of the same bullets measured over the maximum length of the 30-06 which is also 3.340″. The Win.Mag. is fairly new and has about 300-400 rounds through it. I have had some good groups at the range with purchased ammo & reloaded ammo and can hit a 7″ metal swinging target at 300 yards. I think my questions would be, is it safe to exceed the 3.340″ max length and is the difference in the measurements because the 300 Win.Mag. is a belted case? I hope I have given you enough information. Thanks Al !!!!

I think this is an excellent question and it highlights one of the common ways that maximum cartridge lengths are set. The .300 Winchester Magnum was the last of four belted magnum cartridges introduced by Winchester that were designed to fit in a standard length action. It is no coincidence that the maximum cartridge length for a .30-06 and .300 Winchester Magnum are the same, because they were designed to share the same length action and magazine length. When you are using your Hornady O.A.L. gauge, you are measuring the point where the bullet actually engages the rifling rather than its overall length. This length is dependent on bullet shape and the point on the bullet where it actually engages the rifling, rather than the measure from the base of the case head to the tip of the bullet. That is why your measurements are longer. The 3.340” length set for the standard magazine length. It is likely that bullets loaded to the longer overall length will be too long for the magazine and need to be loaded singly.

Is it safe to load beyond SAAMI maximum case length? Yes it is, but there are a couple of points to consider. A bullet seated directly into the rifling will operate at higher pressure than one that has more freebore because it is not free to move before encountering resistance caused by entering the bore. Loads that are near to, or engage the rifling, are typically reduced somewhat to prevent higher than anticipated pressures. Shooters seeking higher accuracy often adjust their bullet engagement before experimenting with different charge weights. Once they have found a good engagement, they begin to work up their charges looking for accurate loads.
The Lab

Ramshot Data for the .44 Special

Here is some data for a great old cartridge that still has a lot of life left. Here’s to the .44 Special. 44 Special vs RS

Christmas Time Data for some old Favorites and Odd Ducks: 7.5 Swiss, 300 Savage, 35 Whelen and 8mm Nambu

The week before Christmas brought us a mixed bag of data requests from old reliables like the .300 Savage to some oddballs like the 8mm Nambu. Here is data to get them all shooting. 35 Whelen vs Accurate 7.5 Swiss using TAC 300 Savage Ramshot 8mm Nambu
Have a Merry Christmas from Labby and the guys in the Lab.

Data for 338 Marlin

Do you have any load data for AA2520 in .338 Marlin Express using the Hornady 200 FTX bullet?
Or any other load data for the .338 Marlin Express?
Thanks, Darron

Here you go, Darron. 338 Marlin Express vs AP and 338 Marlin Express vs RS

Reamer for .270 REN

There are just a few specialty pistols in 270REN in South Africa. I have a fair bit of gunsmithing experience and am a small time commercial bullet caster. Right now I’m casting a batch of 90 grain bullets from a Mountain Mold for those guys. But it strikes me as a handy little cartridge for a nice target rifle for use on short ranges like my own local range. I like to both cast and load my own so I don’t much like rimfire. The 270REN should work well in a Hornet action but also a 223 action if it is a single shot where a slightly oversize bolt face should be OK. But where do I find a SAAMI cartridge and chamber drawing and who makes chamber reamers?
Dick B.

Dave Kiff at Pacific Tool and Gauge should be able to help you. Here is a link:
The Lab

.350 Remington Magnum Data

Have you any info for a 350 Remington magnum?

Here you go. 350 Remington Magnum vs RS and 350 Rem Mag using Accurate

.340 Weatherby Data

Do you have any load data for 340 Weatherby & Ramshot Hunter powder? Bullets I have: (A) Hornady 200, 225 & 250 grain SP; 185 grain GMX; 200 grain SST, & 225 grain InterBonds. (B) Sierra 225 grain Pro-hunters and 250 grain Game Kings. (C) Speer 200 grain SP & 225 grains BTSP. But I can’t find any data using RS Hunter. Thank you

Here is some extrapolated data to get you going. 340 Weatherby magnum using Ramshot

An Expert Answers on Wound Ballistics

Which is a better predictor of penetration, momentum or kinetic energy? Assuming similar bullet performance. Thanks
P. McMullen

Labby had to defer on this one. But Luckily, Charles Schwartz, the author of Quantitative Ammunition Selection was available to field the question.

Momentum is what determines penetration. From page 7 of Quantitative Ammunition Selection:

”While a projectile in motion possesses both momentum and kinetic energy, the penetration of a transient projectile through a homogenous fluid or hydrocolloidal medium constitutes an inelastic collision mandating that it be treated as a momentum transaction. Therefore, a momentum-based analysis of projectile motion is the most equitable approach in constructing a terminal ballistic performance model.”

Newton’s second law of motion, F = ma, is what applies in the case of bullet penetration of gelatin or soft tissue.

Here is a brief, but good, explanation: Impact depth – Wikipedia, the free encyclopedia:. Newton_Penetration_Approximation

8mmX56R Hungarian Data

Dear Labby
I got a couple 8x56R Hungarians when they were running for less than a hundred bucks, part of the reason was apparently the small selection of ammo available. So what do you have in both cast and jacketed loads?
Cheap Joe

You are in good company, Joe. Here is some extrapolated data: 8mmx56R Hungarian M31
Cheap Labby

Reduced 221 Fireball Data

I have two .221 fireball rifles and 1680 is my favorite powder for full power loads, but I would also like to load them to .22 hornet velocities. What is the best power and what are the starting loads? I use 5744 powder for reduced loads in the .17 hornet. Also, do you have any plans to test the .221 fireball with LT-30 power? Thank you,Barry

Here you go, Barry. I enclosed an unusual heavy load, too, but you need a rapid twist. We do plan to test LT-30 in the .221 Fireball. 221 Fireball Reduced loads
The Lab

Reduced Loads for .243 Win, And where is our .22 TCM Data?

Mornin’ Labby
Got any suggestions for a .243 Winchester reduced load, bullets 85 grains and under (mostly under), and did you make any progress in coming up with some .22 TCM load data for rifles? I’d feel a lot better going about loading for it seeing data in print as opposed to doing it by the SWAG method. Too risky! Thanks! Tom L

We are gearing up to test the .22 TCM and anticipate bringing out a powder that will mimic the propellant used for the factory rounds. I can tell you that the data for pistol and rifle will share the same propellants, pressure and charge mass. I’ve enclosed some extrapolated data for your reduced .243 Winchester loads.243 Winchester cast bullet loads with 5744 and 243 Win vs AP

The Lab

.32-20 Data Please

Do you have any data I could use in a .32-20 WCF

Here you go, Sir. 32-20 WCF vs RS 32-20 WCF vs AP

450/400 Nitro Express Data?

I purchased a 450/400 Nitro Express when I dropped by Cabela’s for A-5744…Any data for this behemoth? I didn’t even see it listed in the load manual. Jason C.

We have some extrapolated 450/400 2 3/8th information along with 450/400 3 1/4-inch Nitro Express data. I hope it helps. 450 2 3_8 Purdey 450 NE 3.25
The Lab

Too Much Gun

Dear Labby, what is this company talking about? Is there any way that it has this much muzzle energy?
Roy H. Boise, ID
I had to look twice at that number myself. I found an article about this rifle from the people at “The Truth About Guns” who are a very useful resource.

They can be found at:

They tested the Big Horn Armory Model 89 and got some very impressive ballistics from an equally impressively well-built rifle. The most powerful round they tested was the Double Tap 400-grain load at a chronographed 2,240 fps which developed 4,457 ft/lbs of energy. By way of comparison, Hornady’s 750-grain AMAX .50 BMG load generates 2,820 fps for 13,241 ft/lbs.

What I think we have here is a disconnect between the marketing department and the people who work with guns. I suspect they accidently added a zero. For the fun of it, I looked at what would be needed to get up to the published 36,800 ft/lbs of energy. The numbers are pretty big.

The formula for muzzle energy is pretty easy as long as you have a calculator that has a lot of zeros.

ME=Velocity*Velocity*Bullet Weight/450240.

Drum roll please: The Model 89 would need to increase the Double Tap 400-grain load to 6,438 fps to make 36,800 ft/lbs. has a neat little Recoil calculator that was able to estimate the recoil this 7 lb 10 ounce rifle would generate with this fictional load. It suggested that 364 ft/lbs of free recoil would be the result. The same weight .458 Win. Magnum topped out at 81 ft/lbs.

To answer their question: Is 36,800 ft-lbs Enough Gun? Given these numbers the Model 89 would be Too Much Gun. It is an awesome gun at 3,680 ft/lbs, though.

9mm Largo Loads

Anything for the 9 Largo?
I for one do not ascribe to the “use 38 super they are the same thing”. I have in the past had to use 38 super brass in the absence of 9 largo but loaded with 9 largo data. Got anything that will make the old Spanish Steel shine? (Used mainly in Star Supers and P&R Medusas) Joe M.

They are not the same thing. I couldn’t agree with you more. Here is some extrapolated data to get your Largos shooting. 9mm Largo vs AP
The Lab

8X57 Cast Lead Loads

Hi, I shoot an 8×57 JS Mauser with 170 gr. cast (wheelweights) gas checked bullet. Can you help me out with some load recommendations? If I decide to shoot them plain based, can you also suggest a load?
Thanks! Reed

Here you go, Reed. 8mmx57JS Mauser vs AP

7.62X25 Tok Data

I remember some time back having load data for aa#7 but cannot find any now in 7.62×25 . I am looking for some data for this cartridge. If you could help that would be awesome. FYI It will be fired from a very good condition CZ-52.

Here you go, Matt. 7.62×25 Tokarev vs AP

We Need New .38-55 and .22 PPC Data

Hi do you have any newer reloading data for the 22 PPC USA? The newest data I’ve got is in the Accurate reloading manual from 2003. This was with 50 and 55 gr bullets and the powders 2015, 2230, 2460, 2495 and 2520. Seems weird as the 20 PPC wildcat (along with a load of other 20 wildcats) is in there, as is the 6 mm PPC, but not the 22 PPC?
I was also after data for the 38-55 WCF for both a Marlin 336 CB and Pedersoli Sharps (both proofed to standard CIP level for the 38-55, 2,400 bar/34,800 PSI). I can’t find any Ramshot data and the Accurate data harks back 2000 reloading manual.
So, in general, I guess I was wondering is there was any load data for current Ramshot and Accurate powders for each cartridge?
Neil G

We don’t have any new data for the .22 PPC nor for the .38-55 but the later has been added to the testing list. Here is extrapolated data for both. 22 PPC and 38-55 data
The Lab

Why No 9.3 cal. Data?

I saw in a reloading magazine an author recommend TAC for 9.3×62. Never thought of TAC for this round before! I also see that you don’t list 9.3×62 in your reloading data online.
What gives Labby?
Wendell R.

If we were a company based in Africa, I would prioritize testing of 9.3 caliber cartridges. Right now, we just don’t have the resources to shoot lab data for every cartridge out there, but if we do elect to test a 9.3, the 9.3X62 will be the first on the list.  It is a great cartridge. I’ve included extrapolated data to get you going.  9.3×62 Data  To ease the sting of us ignoring the 9.3 caliber for now, I will send you a hat if you will send me your mailing address.

Why No Max Load for Subsonic .300 Blackhout


No, it isn’t a misprint. The data is limited by the speed of sound.
The Lab

.458 Winchester Magnum Gopher Loads

I’m going to use my .458 Win Mag for gopher hunting. Do you have reduced loads? Thanks for your help in advance, Uncle Stumpy.

Here you go, you lunatic:: 458 Win Mag vs AP

.357 Pistol bullets for .358 Win. Plinking Loads

I would like to load 158 gr. Semi-wadcutters in my .358 Winchester for plinking loads. Do you have any data I can use? Tom T.

Sure, Tom. Click here to download the data: 358 Win 158 Semi-wadcutter

.32-20 Rifle Data

I have a Marlin 1889 Lever Action Rifle, in .32-20, that I shoot in “Cowboy Action”. It has a long barrel, with the 10 round magazine. I am looking for smokeless loading data, using a 100-115 gr. lead bullet. I have found lots of revolver data, {witch is fine}, but little for rifle. Do you have any suggestions for your line of powders? Thank you for your time. Larry Aljets PS The rifle could use a relining of the barrel; could you suggest someone? I live in the Tulsa, OK area Thanks again, Larry A.

This is data that will be out in our new, full-size handloading guide. You are getting a sneak peek. 32-20 Rifle The Lab

What is a Piezo Transducer?

Dear Labby,
Can you give a little detail to the piezo transducer and it’s operation? How does it function? Where would you screw it into on the M1 Garand. The AR-15? The 1911?
Bill M.


The bottom of the piezo is cut to match a case's body. The threaded end is connected to the pressure gauge.

The bottom of the piezo is cut to match a case’s body. The threaded end is connected to the pressure gauge.

The first image is of a piezo transducer in action as part of regular testing. In the American system, the transducer’s base is radiused to match the case body. When the cartridge is fired, the case expands crushing the piezo which creates a spark, the intensity of which can be directly translated into PSI. In the Garand, the lab used a modified gas plug to get the port pressure readings. For AR 15 military testing, a transducer is mounted at the case mouth and another at the point where the gas block would sit on the barrel. garandplug72The 1911 , a delayed blowback, doesn’t have a gas system. Testing for that type of pistol would rely on cartridge pressure testing from a test barrel.
The Lab

50 AE Data

Hello, do you have any load data for .50 Action Express? I enjoy using your powders but this is the only caliber I have that I can’t reload with any of your powders 🙁   Hugo

Here you go, Hugo 🙂  50 AE vs AP

Keeping the 40-82 Winchester Shooting

Do you have load data for 40-82 Winchester using accurate 5744?  TK

We do:  40-82 Winchester

7.5X55 Swiss Data

I have just bought a Swiss K31 and would like more loading data for it. I have 150, 165 and 180 grain jacketed bullets and 160 grain cast. I have on hand ACC2520, ACC4350 and ACC5744 that I think should be suitable for the 7.5×55 Swiss but no data. Can you help me? Thanks, G. B.

Here is some extrapolated data to get you going.  7.5×55 Swiss AP

.45 Winchester Magnum Data

Could I get some data for the .45 Winchester Magnum? Tom H.

Here is some to get you started, Tom. 45 Win Mag
The Lab

Magpro in the 9mm Parabellum

I’ve found no data in your charts for loading 115GR FMJ 9MM with Magpro. Store I purchased from assures me that it can in fact be done. Any help?
Thanks, Dan T.

It just will not work, Dan. Magpro is currently the slowest powder available from the Accurate Powders line. You could compress the powder until you swelled the case and still not guarantee enough velocity to get the bullet out of the barrel. It is important to have an idea what powder you are looking for before you purchase. There is information on the back of each canister that will give some useful hints regarding the powder’s most common uses. If you are still unsure or want to know if there is data for your specific cartridge choice, we are just a phone call away during normal business hours 8-5 Monday through Friday with an hour break for lunch from 12 to 1. You can call 406-234-0422 and ask for customer service.
The Lab

Loads for .577-450

I am a big fan and consumer of your 5744 Powder. Do you have any load data suggestions for using 5744 in the 577-450 Martini-Henry British Army rifle? Or for that matter any smokeless powder load for the 577-450. It appears that when looking on the Internet that there are a large number of reloaders who use 5744 wanting to use it in the 577-450 cartridge, I am one of them. I relealize that the large case volume presents a challenge for other than black powder as the original loading.
Thanks, Tom P.

Here is some data to get you started. 577 450 Martini Henry 5744

Pressure Vs. Velocity

Does Higher Pressure Equal Higher Velocity? Tom H.

No, sometimes it is just higher pressure. If you fill up a 9mm Luger to the gills with a very fast powder, the pressure curve rises more steeply than the velocity increase, they do not rise in lockstep. Usually a slower powder at a lower peak pressure will beat over-pressure fast powder charges for producing velocity.
The Lab

Data for the .45 Schofield

Do you have some data on the .45 Schofield?  Louis S.

We don’t have any shot data, but here is some extrapolated data to get you started.  45 Schofield Data

LT-32 and the .22-250

Need load data for lt-32 in 22-250. Steve M.

LT-32 is too fast to be a good performer in the .22-250. I’m sorry, we have no data to offer you.
The Lab

Reduced Loads for 7.62X54R and 7.65X53 Argentine

I have a Mosin-Nagant Model 1891, 7.62X54R, and a Argentine Mouser Model 1891, 7.65X53. I would like to shoot these two rifles using 5744 powder with a lead RNGC 200 gr bullet. Keeping it at or below 1800 fps.
What is a good starting load? Can this 5744 powder be used in shotguns and pistols?
Art T.

A5744 is an excellent powder for reduced rifle loads and can be used in some large capacity pistol cartridges. It is too slow to be useful in shotgun shells. Here is your data: 7.62 x 54 Russian Reduced7.65 x 53 Arg Mauser Reduced

Accurate #2 vs. #2 Improved

What is the difference in load when using No 2 Improved v. No 2???
Is there a conversion factor?

The original Accurate Arms Company changed the bulk density of #2 ostensibly to give better case fills for low pressure loadings like .45 Colt and the .38 Special. The load data is the same as Accurate #2.
The Lab

Data for the .303 Savage

I’m looking for .303 Savage data — Can you help?
T. Poss

We don’t have much but here it is 303 Savage data

Loading Information for Data Powder 68

What data should I use for Data Powder 68?

Data powders were batches of military pull-down or short runs of powder that would not typically be available as canister products. Some like A2200 were popular enough that they were later added to our line. You can find the data by going to the Accurate website and clicking on “Load Data.” Click here to get the Data Powder 68 information: DP68

.30 Carbine loads with 100 gr. bullets and A4100

I need load data for 30 Carbine rifle using 4100 powder and 100 grain jacketed JHP. Any help you can render is greatly appreciated!
Eric T.

Here is some extrapolated data to get you going. 30Carb_A4100

Best Twist for 9mm Autopistol Barrel

What do you think is the best twist for the 9mm Luger using 115 grain bullets?
Stacy R. San Francisco CA

Ideal twists are a bit out of our wheelhouse. Schuman Barrels offers a pretty insightful pdf on how they settled on their production twists. Click here for the pdf: Webfile_Barrel Twist Rate
The Lab

Action Speed and Powder Speed Linked?

As with other locked breach semi-autos, the action of a Luger is operated by the movement of one part against another under recoil.
As you know, the 9×19 cartridge was developed in 1902, One of the arguments for the Luger’s supposed problems with modern ammunition is that the recoil of the original cartridges (circa 1908) gave “a longer, slower push” than modern cartridges. Obviously, propellants have changed since 1908, so maybe that argument is — kind of plausible.
However, it seems to me that bullets of the same weight and achieving the same muzzle velocity from a given barrel are necessarily undergoing the same acceleration and should produce nearly identical recoil forces, both in terms of total force AND the curve of the way that force distributed during the about ½ millisecond the projectile is in the barrel.
That is, if bullet weight and the resulting MV were the same, the recoil forces “felt” by the gun (and the speed with which the moving parts move) would be the same whether the propellant were a “slow” shotgun powder or detonation of an appropriately sized drop of nitroglycerin.
True or false for the recoil forces? (I suppose the nitroglycerin charge might have other effects).
Arthur B.

Within a very short time-frame, I believe your statement is correct. Pressure is pressure and Newton’s Third is alive and well. The differences I see in terms of reliability of slower powders in autopistol cartridges, especially the 9mm Para relates to the relative amount of gas that is created by the powder supply. It takes more slow powder to bring a cartridge to pressure. The increase in powder translates into more gas driving both the bullet and action, typically with lower peak pressures. Given a choice, I would always use the slowest powder that was practical for a given pistol cartridge.
The Lab

Why Use Different COL’s for the Same Weight Bullets?

In the Western Powders loading data, for the same cartridge, powder and bullet weight, you will list different COL. For example, the 223 Remington and X-Terminator powder with 55 grain Hornday bullets:
55 HDY BT-FMJ 2.200
55 HDY SPSX 2.195
55 HDY V-MAX 2.260
Why do you use different COL when the cartridge and powder are the same?
Daniel W

Depending on their style, bullets of the same weight can have very different shapes that effect internal ballistics.  Most manufacturers have suggested overall lengths for their bullets, which we usually try to approximate in our testing.  Some of our tests use different parameters that call for a shorter or longer COL.  Magazine length can also effect COL selection, as is often the case with the .223 Remington.
The Lab

7.5X55 Swiss

I’ve been using your powders for almost twenty years and have always been pleased with the quality and performance they provide. The PDF reloading guide is a pleasure to use!  Now if you could get a 7.5X55 test barrel and work up some loads for my old Swiss rifle I’d be elated. sincerely. J. P.
Here are some loads to get you started with your Swiss rifle.  7.5×55 Swiss
The Lab 

Fast Powder Fails to Cycle

I have a Taurus PT908 pistol in 9 mm that has a pretty rugged recoil spring
I’d like to get a lighter one but they are not available.
Many factory loads will not run this gun at all reliably
My handloads have to be well up into +P to function
Right now I’m using up a ton of 125 grain round nose lead with a stiff charge of Bullseye.
A friend who absolutely swears by Accurate Arms has suggested I ask your recommendations. He thinks that the recoil impulse of Bullseye may be too fast
Thank you for your consideration, TR

I did the same thing with the first pin gun I had built more than 20 years ago.  It just didn’t want to run until I was at very high pressure with Bullseye and even then it wasn’t terribly reliable.  I think the cure here may well be a slower powder running at higher velocity with similar or lower pressures to the ones you are getting with you fast powder choice.  I think I would try #7 first and then #5 or True Blue to see if you can make your pistol run smoother and more reliably.

The Lab 


Loads for a Pedersoli Sharps .45-70 Gov.

Dear Labby
I have a Pedersoli Sharps 45/70
I mold a 520gr .459 1:20 lead Money Bullet
AA5744 is my powder of choice for cast bullets in all my calibers I load for. Load data for Lead bullets ends at 500 gr. in the 28000 range.
Can you provide a starting point in grains for the 520 gr bullet using 5744 powder please?

Here is data for both 18,000 psi Trapdoor Springfield loads along with higher pressure loads for modern rifles. 4570_5744_LowPressure and 45-70_5744_28KPSI
The Lab

.32 H&R Magnum Data

I don’t see any 32 H & R Mag Reloading data in the Reloading guide, Is there anyr load you can recommend.
Rex R.

Here is some extrapolated data for your very useful little cartridge.
32 H&R Magnum Data
The Lab

Wadcutter Weirdness

In the load data book Page 26 for 38 Special +P with Accurate #5 and Berrys 148P DEWC it shows a COL of 1.140 inches. The trim to length for this casing is 1.145 inches.. How can the COL be shorter than the trim to length? This is the only data that I have found for these DEWC and I do not have a lot of experience reloading, so if I am missing something please let me know. Thank you very much in advance.
David M.

.38 Special Wadcutter

.38 Special Wadcutter

Wadcutters were all the rage for bullseye competition not so long ago, but they are less common of late. The bullet is set slightly below the case mouth, which is then crimped over the bullet. They look strange but shoot quite well.
The Lab



.32 Winchester Special Data

I’m trying to find load data for .32 Winchester Special. I realise that this is an obsolete cartridge, however I still have one, and the loading dies and components are still available. Thank You.
John O.

We don’t have pressure tested data, but here is extrapolated data to get you shooting. Click here to download the pdf: 32Specialdata

More 7X57 Mauser Data

You only listed two series of loads for the 7×57 in your latest reloading data. However, I sent off a question about best loads for the cartridge and I received a reply that Big Game was an excellent choice. I used it this past fall with a Barnes 120 grain bullet and achieved spectacular humane kills at 200 yards. Why haven’t you guys listed Big Game or Hunter Powders for this superb old cartridge?
Peter D.

The data you got by request was extrapolated information developed by pressure modeling rather than test data from a pressure barrel. I have the 7X57 scheduled for another round of testing this year. Ramshot powders will be tested and included in our published guide data. We’re pleased the data worked well for you. 7X57_ramshotdata
The Lab

Why Do Shotguns Use Fast Powder

Why do shotgun shells use the fastest burning powders?
Daniel W.

Smokeless powders require pressure to burn properly within a cartridge. In rifled firearms the bullet acts a pressure plug that seals the bore; allowing pressure to peak and then decrease as the bore volume expands with the bullet’s travel down the barrel. Shotguns achieve pressure primarily by the powder charge acting against the weight of their shot column. The fastest powders work against the payload weight in a sudden push that gets things moving because there is little resistance once the payload leaves the chamber and moves into the smooth bore.
The Lab

.375 H&H Using A4064

I am loading for the 375 H&H using 270gr and 300gr bullets. I have an 8 lb keg of AA4064. I cannot find any data with this powder in the 375. Do you have any recommendations?
Respectfully yours,
William S.
Here is some data that might help. .375H&HA4064
The Lab

Data for 9mm Makarov and 7.62X25 Tokarev

I reload for 7.62×25 Tok and 9mm Makarov. Wish you would show some data for these two calibers. Data is skimpy for these two.
Thanks N.S.

We hope to have data from our pressure barrels for both of these great cartridges in the future. In the meantime, we have included extrapolated data that will keep your shooters shooting. Download this PDF to access data for the 9mm Makarov and 7.62X25 Tokarev.9X18Mak_7.62Tok

Shelf Life and Packaging Dates

Does powder ever get to old to use and what identifing marks does your company put on the canister for when it is made, You have helped me out a while ago when I asked about keeping my cowboy shooting under 950 fps and it works great less stress on the hand and the recoil is very minimum.
thank for you time..
Mr R.B.

Date and Lot codes are in the upper right-hand box.

Date and Lot codes are in the upper right-hand box.

his code indicates the powder was poured on January 27th, 2015 from lot 465

This code indicates the powder was poured on January 27th, 2015 from lot 465

On one pound bottles, the number is on the corner in a silver box. If the powder was poured today, it would read 012815 followed by a lot number. The whole number would look something like 012815749. Eight pound bottles have a sticker on the bottom with an obvious date code. The lot number appears above the date.
Powder can have a very long shelf life. You need to watch for changes in smell and color. A reddish tinge, almost like rust on the powder, is a bad sign, as is a foul odor, not to be confused with a normal chemical smell. Either of these signs indicate it is time to dispose of your powder by means other than shooting.
The Lab

7mm TCU Data

Do you have any data for loading the 7mm TCU?

We don’t have tested data, but guys in the lab were able to extrapolate some loads for you.
The Lab

Proper Powder Storage

I live in southern Arizona where it is very hot. I am told powders will become unstable if stored in an area not air conditioned. My wife says no powder or primers in the house. Can powder be stored in a refrigerator? What about using a fireproof safe? I would appreciate your ideas. Thanks

SAAMI guidelines are pretty clear on issues of storage. They recommend storing smokeless powder in containers that will not allow pressure to build if the powder is ignited; ruling out gun safes and refrigerators.

In their original containers smokeless powder’s lifespan is quite long, even in your hot, arid climate, typically longer than the average handloader would need to store them. Stored safely in a garage or outbuilding, your powder should last years.

If you see the powder developing a reddish tint, or giving off a foul odor, it is time to discard it.

Click here to read SAAMI’s guidelines for powder storage.
The Lab

Understanding Bullet Trajectory

Why does a bullet raise up? When you plug in your bullet into a computer it’s always high for a while and then low. My friend says that its spin makes it roll up above where you aim in the first fifty yards and then it drops back down. Is that right?

Trajectory tables provide very useful data for the shooter, but they do it in a way that is misleading. The data is based on where the bullet will be in relationship to your sights, but it doesn’t explain why it is there. The idea of “Bullet Rise” comes from a fundamental misunderstanding of how bullets fly and how sights interact with the bullet’s arcing trajectory.

The common bullet drop tables look something like this for a rifle zeroed at 200 yards:

Muzzle: -1.5 inches
100 Yards: +2.4 inches
200 Yards: 0
300 Yards: -10.9

These numbers are very accurate from the shooters perspective which is called the Line of Sight. Looking at these numbers, it is easy to see that the bullet is describing an arc, starting 1.5 inches below the Line of Sight, which is the distance between the center of the bore and the center of the sight plane. The convergence of the Line of Sight and the bullet’s trajectory takes place at 200 yards. In other words, the bullet goes where your sights indicate it will strike. Using the Line of Sight as a reference, and as long as we are shooting on Earth, all firearms will strike to the point of aim at two places in the bullet’s trajectory.

Imagine a very powerful laser projecting out of your firearm’s muzzle. This straight line is called the Line of Departure and represents the starting point for your bullet. Relative to this line, your bullet is always dropping away from the bore subject to the effects of gravity. It does not rise above this plane.

Parallel Line of Sight and Line of Departure Planes.

Parallel Line of Sight and Line of Departure Planes.

The confusion comes from the idea that the Line of Sight and Line of Departure are parallel and that the bullet rises up to the Line of Sight and then drops back down. If this were the case, it would be impossible to zero a firearm. In reality, the Line of Sight is always angled downwards so it will intersect the bullet’s path. It may seem counter-intuitive at first glance, but the further out a rifle is zeroed the more sharply the Line of Sight is angled toward the Line of Departure.

trajectory72A bullet fired on Earth is subject to a number of forces that will retard its motion and eventually cause it to strike the ground. Because of these forces, a bullet passes back through the Line of Sight as gravity pulls it back toward Earth. This second point of convergence is usually where a firearm is considered zeroed.

So, if you set the zero for a (fill in the blank here – let’s say a 6.5 Snorkelwacker Magnum) at 25 yards, that distance becomes the first point of convergence for the Line of Sight and the bullet’s trajectory. The bullet will pass back through the line of sight again somewhere around 200 yards. The bullet is always falling away from the Line of Departure (your bore), but because the Line of Sight is looking at an angle downward into the bullet’s arc, its trajectory seems to rise and fall.
The Lab

Are Compressed Loads Safe?

I was wondering about the 300 BLK loads listed from your site. It says I can load 19.9 grains of 5744, but when I do it comes up near the top of the brass. I heard people mention something called a compressed load, but can you help me be clear so I don’t create any risks? Thank you!

Compressed loads always deserve careful consideration when used by handloaders. Compressed powders can exhibit unique characteristics which varies between cartridges and bullet weights. The data presented in our guide has been tested in our ballistics lab, using ammunition fired through specialized pressure barrels, and found to be within SAAMI pressure tolerances. Even though this data produced acceptable pressures in our lab, it is still necessary for all handloaders using this data to begin with the starting load and carefully work up to the maximum loads while watching for overt signs of pressure.
The Lab

Unpublished Load is Causing Problems

I am loading 42 grn ramshot magnum in a 45/70 case. the problem is after each shot there is unburned powder in the barrel. ! J.C.

The real problem is that you are using a powder that is ill-suited for the application. There are usually sound reasons why data isn’t provided for certain cartridge/powder combinations. This is one of those. Ramshot Magnum is too slow for the .45-70 Gov’t. Unburned powder is a sign of incomplete ignition caused by very low pressure. The slowest powder we have published data for is Ramshot X-Terminator, which is substantially faster than Ramshot Magnum. Sticking to published loads will prevent many problems, including the one that you are experiencing.
The Lab

Magnum Primers in the .45 ACP

I want to load some .45Auto but I only have CCI magnum large pistol primers. Can I still load using your guide? Should I lower the charges?
Primerless in Laramie

Yes, you can use magnum pistol primers when standard primers aren’t available. They should work fine, but it is anybody’s guess whether they will create more or less pressure than the published loads. The best method when any component is changed is to reduce the charge, load a few, test them over a chronograph and compare the velocity to our printed pressure/velocity guidelines. If your loads produce similar velocity to our tested loads (given similar barrel lengths) the pressures are also similar. If you are faster, or show obvious pressure signs, then reduce the load until it approximates the published load. If slower, increase the charge weight until the desired velocity it obtained.
The Lab

A Girlfriend or My Guns

My new girlfriend is good looking, but she is liberal, hates dogs and guns. What should I do, Dear Labby?

Labby was confronted by a situation similar to this while he was in the third year of his freshman year of college. She was a liberal beauty with a figure that wouldn’t quit. During our romance I purchased a new Browning Hi-Power with great bluing, clean lines and good checkering. A recent look at Facebook reveals that her figure has quit, but the Browning still looks great. Guns keep their looks if they are well cared for, and a dog will love you forever. It’s more hit and miss with women.
Labby Himself

.22 Long Rifle Data Request

To: The Lab
From: Me
Why don’t you finally publish data for .22 LR? I mean, what is the hold-up? If we could reload our own .22’s, then the market glut would end like right now! (I’ve been saving the brass for decades, and boy! do I have a ton of it!) Of course, I suspect the reloading dies would be expensive–just how do they get those primers to stretch and form around the bullet like that without setting them off!?
Yours Truly,
Awaiting .22’s
P.S. Yes, I’m teasing.

We are still behind on our 5mm Rimfire data, but once that is done we can get started.
The Lab

Minimum Dimension Barrels in 9mm Para.

Years before Western bought Accurate Powder Co. and while Johan Loubser was Accurate’s ballistician, he furnished me with .45 ACP +P data. It was great because the 185 & 230 gr. Golden Sabers were listed for charges using AA#5 & #7. The thing is, the data also included the same weight XTPs where the same charges produced pressure as much as 2000 PSI higher for the XTP with velocities running higher as well by at least 50 FPS over the Golden Sabers. This holds up in my experience where an equal charge of True Blue or Silhouette will yield lower velocity using Golden Sabers in comparison to XTPs. Your current data states exactly the opposite with Golden Sabers getting higher velocities with lower charges. I realize that some of your .45 ACP data is newer and includes the Golden Sabers where XTP loads haven’t really changed. The Golden Saber is, of course, brass jacketed and has much less bearing surface than the copper jacketed XTP. This has raised a couple of questions for me and I’ll get right to the next.

In 9 x19mm it’s the exact opposite in your data where the 124 gr. Golden Saber, in particular, gets higher charges than other JHPs of the same weight. The Golden Saber data is also newer than for some of the other JHPs of the same weight. I’ve also seen a downrating of your 9 x 19mm data in recent years. I witnessed the same occurence years back with Vihta Vouri powders when they started using minimum dimension test barrels to keep their American data closer in line with SAAMI than CIP. So, are your pressure ratings for 9 x 19mm and .45 ACP now being gathered in minimum dimension chambers that raise pressure higer than typical pistols? Your 9 x 19mm +P and .45 ACP +P data also appears to be rather weak which further raises my suspicions that Western has gone to using minimum dimension test barrels.

Hi Kevin,
I was somewhat confused reading your questions, since some of your statements seam to contradict each other. So I will try and generalize what I believe you are asking. First off, I cannot speak for anything that was done by the Accurate Arms Company prior to Western Powders acquiring the Accurate Powder line from them. I can tell you that we have slowly been weeding out their data and that the 45 ACP data you speak of was corrected in the Accurate #2 revised edition.

Customers are always claiming that we de-rate our load data to avoid lawsuits—THIS IS JUST NOT TRUE. SAAMI (Sporting Arms and Ammunition Manufactures Institute, INC.) sets the voluntary standards of the US gun industry. They provide specifications and tolerances for all of the SAAMI approved cartridges. There specifications cover maximum pressure ratings, dimensions, and tolerances for a given cartridge. You can easily access the cartridge drawings on their website, as well as the European CIP standards on their site. In reviewing the drawings for the 45 ACP and 9mm Luger, there is very little deviation, and if there was any, the CIP dimensions seemed to be tighter. To me, this disproves your theory of Vihtavuori reducing their load data to meet SAAMI specifications by using minimum spec SAAMI chambers.

Almost all reloading data will have a disclaimer stating to always use the most recent load data or that the new supersedes all prior data published. There are two main reasons for this:

1) If you never make a mistake—chances are you are not doing anything. Mistakes can and do occasionally happen, and when they do they need to be corrected and learned from.
2) The second and most important one: as we grow in our experience; testing equipment and procedures become greatly improved.

At Western, we use Piezo transducers to measure all of our chamber pressures. This is a more accurate and precise form of measurement compared to the old Copper Crusher style testing. There are many claims at a conversion factor from CUP (Copper Units of Pressure) to PSI, but it is not possible. As SAAMI moved from CUP to PSI, cartridges either gained or lost ground in regards to pressure and velocity standards. However, what ever specification they set—that becomes the new standard for us to abide by.

The best way to perform the most accurate comparison of bullet performance; is to use the same cases, primers, powder, firearm and to shoot them one after the other on the same day. There are just too many variables that effect performance in a loaded round. Every component of a cartridge varies from one lot to the other and can still be within their tolerance. Temperature, humidity, altitude and barometric pressure can all change how ammunition performs. We try and to control as many variables as we can when testing in the lab, but this is not an option when shooting in real world situations. You are correct in the fact that some of the JHP data is not as new as the Remington Golden Sabre data, which makes for a rough comparison. Here are some truths and observations I can share when comparing the Hornady XTP bullets to the Remington Golden Sabre bullets:

1) The GS bullets do have a shorter bearing surface reducing friction and lowering pressure. While the XTP bullets appear to have a thicker jacket as well as a much longer bearing surface.
2) The GS bullets use a longer COL than the XTP bullets; this opens up usable case capacity and also lowers pressure.
3) Since pressure is the limiting factor in reloading ammunition, the bullet that produces the lowest pressure (GS) will have a maximum charge weight that exceeds the maximum charge weight of the higher pressure bullet (XTP).
4) Powder burn rate, and velocity to pressure ratio tend to remain fairly constant. Thus the bullet running at a lower pressure will be able to achieve a higher velocity at the maximum powder charge weight.

Some of the variation between the 45 ACP and 9mm Luger XTP/GS load data is created by the difference in COL. In the 45 ACP there is a COL difference of .015”, while in the 9mm the length difference is .085” in a much smaller case running at a much higher pressure. In our conclusion, the Golden Sabre bullets should achieve more velocity at a higher charge weight for any given pressure than the Hornady XTP.
The Lab

Accuracy Poor with Lighter Bullets

I loaded up some 6.5 Swede as follows, 40 grains of Accurate 4350 with a 140 grain boattail spritzer bullet and achieved 1.5 inch groups at 100 yards with mild recoil. Next I seated 100 grain boattails spritzers on the same charge of powder. I expected increased accuracy due to higher velocity. I was surprised that I could not get better than 6 inch groups. All things being equal, doesn’t more velocity yield flatter more accurate bullet tracjectories? Rifle is a modified sporterized 6.5 Swedish Mauser with a 16 inch barrel.

When you decreased the bullet weight, you also decreased the pressure developed in your load. Your velocity increase may have been pretty minimal. More velocity does make for a flatter trajectory (although that advantage may fade quickly depending on the ballistic co-efficients of the bullets you are comparing) but that does not make a round more accurate. Your Swede, if it is still using its original barrel, was twisted to favor heavy bullets and it still seems to be showing its affinity with the first load. I think you should accept what it is telling you and stick to longer, heavier bullets.
The Lab

Help Us Choose Cartridges to Test

We are looking for your input to help schedule testing over the next year. The top three cartridges will be added to our testing schedule. From now until October 1st, we are asking you to send us your suggestions. Just type them in and submit them through the Dear Labby Q and A section on the left side of your screen. We will announce the top three finishers in early October.
The Lab

Mining Gunpowder in Montana

Do you mine the powder right there in Miles City? Is that why you are located in Montana? Is it possible to add another shift or something to increase production?

We passed this one around a bit wondering if you were teasing us. You probably are, but it is a reasonable question. No, we don’t mine for gunpowder here in Montana, although the thought of a rich vein of Accurate #2 does tend to make us wish the idea was true. Our powders are all man-made using some very complex chemical interactions and production tools. If your question is really about powder availability, we are doing everything we can to bring as much powder to the market as possible. We hadn’t thought of mining for powder, but if it did work we would be doing it three shifts a day.
The Lab

Developing Loads for Different Seasons

I have a question about reloading in the context of seasons. I live in Las Vegas, where in the summertime it’s common to have highs around 110 F. Winter by contrast can have overnight lows around 28 F with daytime highs anywhere from 40’s to 60’s depending on the year. I read recently that changes in temperature can affect pressure. I’m currently in the early stages of developing loads for service rifle. I have some SMK 69 gr, 80 gr, and Hornady 75 gr bullets and a variety of powders. I’m going to be using Lapua .223 brass, and am currently at the bottom end of the powder weights for my loads. What should I be doing to ensure my pressures don’t go too high because of temperatures. Should I only develop loads in summer? I’m thinking a winter developed load that is safe could become unsafe if fired in summer in this climate.

All powders are affected some by temperature, but the amount of difference varies by cartridge and components used. In the .223, you shouldn’t see a dramatic change in pressure and velocity with any of our powders suitable for the cartridge. For any given cartridge, your best shot at year around accuracy would be to develop loads during your average hunting temperature. So in your case, I would recommend developing and testing loads around 69 deg. F.
The Lab

A2230 Data matches Ramshot X-Terminator

I’ve noticed on the updated data for the 7.62×39 (5.0.1) that the powder charges for Ramshot X-Terminator and Accurate 2230 are exactly the same, all entries are exactly the same. Is this correct data for these two powders?

In this case, it is correct. Ramshot X-Terminator and Accurate 2230 are the same powder used by both powder lines.
The Lab

CUP to PSI: Is there a Formula?

How do you convert CUP to PSI?

There isn’t a good mathematical conversion between Copper Units of Pressure (CUP) and PSI measurements. CUP was based on measurements taken from small cylinders of specially formulated copper after they were subjected to crushing pressures. Conversion tables were supplied with each lot of crushers to index them to the CUP scale of pressure. The system doesn’t directly correlate to measurements in Pounds/Square Inch. Any formula which purports to link the two systems should be treated with skepticism.
The Lab

Finding Maximum Cartridge Length in a Chamber

How can I find the Cartridge Overall Length for my rifle?

There are a couple of great tools made by Sinclair and Hornady (just to name a couple) that make the job quick and easy. I’ve included a quick how-to using another method it in a separate article because it is long on pictures. Look down the page to find the story.
The Lab

.357 Remington Magnum Mistake

When I was younger we always called the .357 Mag., .357 Remington Mag. After reading older books from around the time the cartridge was developed it was said to have been developed by Winchester. I see you refer to it as Remington too. Did Remington finish the development or some other reason or were the books wrong?

We did refer to the .357 Magnum as the .357 Remington Magnum in a previous “Dear Labby” answer. After researching your question, the simple answer seems to be that we were wrong to attribute this cartridge to Remington. Your suggestion that Winchester was part of the development team along with Smith and Wesson is spot on. The .357 Registered Magnum was announced by Smith and Wesson in 1935. Perhaps it is the “Reg.” abbreviation’s closeness to the “Rem.” that led to this mistake, or Remington’s later association with the .357 Maximum, 41 and 44 Magnums that bring its name rolling off the tongue. No matter the reason, Remington’s name doesn’t seem to belong with this cartridge. Its proper nomenclature is .357 Smith and Wesson Magnum or the simpler .357 Magnum which is how the cartridge is identified by SAAMI.
The Lab

Academics and Lab Staff

I had two questions; what type of schooling does a person need to be qualified for becoming a ballistics tech? Second, for the powder burn in a handgun, does it have a complete burn before the bullet even leaves the crimp? How does it show up on the timeline; the powder burn time in relationship to the bullet travel?

While there isn’t a college program dedicated to the sporting arms and ammunition field, there are a few degrees that will make life easier. A degree in Forensic Science, mechanical engineering, physics, chemistry, and or aerospace are all helpful in the ballistic world. A keen attention to detail, as well as familiarity with lab equipment, word processing, Microsoft excel; and a machining background all makes for good skill-sets in a ballistic lab.

Powder burn can vary by component selection and caliber. Generally for handgun calibers, peak pressure is reached before the bullet leaves the case, but complete powder burn may never be achieved; depending on barrel length and powder burn rate.
The Lab

What is “Muzzle Energy”

What is “Muzzle energy” and what does it mean?

Calculating muzzle energy provides a quick tool for comparing energy between various loads or firearms. It is a simple formula that uses the velocity of bullet (V) and the weight of bullet (W) divided by a constant to produce a measure of energy (taken at the muzzle) in foot/pounds. The formula is V*V*W/450240. What it means is a more difficult question. Muzzle energy is not a good predictor of terminal performance on game animals because it does not consider bullet design and performance. It simply tells you how much energy is present at the muzzle based on the weight and velocity of a projectile.
The Lab

Changes in 9mm Luger Data

I have been reloading 9mm shells using the data in the Reloading guide 5.0.
I have been using Ramshot Zip for my loads, with Frontier 115 gr CMJ bullets (I called your company when I bought the powder and bullets and was told to use the same data as the Sierra FMJ) with my Lee Pro Auto-Disk Powder Measure dispensing at an average rate of 4.0 gr of the powder (3.9 – 4-1). Everything seems to be going fine, and I have had no FTEs or FTFs.
Now, I see via the 1/24/14 update that the loads should be considerably higher (4.4 – 4.7).
Is there a problem with what I am doing?

There isn’t any problem at all. The data you are using is for standard 9mm Luger loads at an average pressure of 35,000 psi or less. The new data you saw is for +P loads which operate at about 38,000 psi as a maximum. Your loads are fine, the others just offer higher pressure and velocity for firearms rated to that level of performance.
The Lab

Same Case, Different Manufacturer, Same Pressure?

All the reloading data that I have will call for certain brands of components. I understand that primers and powder will make a difference in pressure. But how about the brass that is used, does it make a difference in pressure? Can you use Winchester brass when it calls for Remington?

Brass can make quite a lot of difference in pressure, mainly because of variations in case capacity. Our lab tests pressures using cases produced within the same lot to keep this variation to a minimum. Between manufacturers, especially on cases produced outside the United States, there are differences in capacity. You can handload with Remington brass using data that calls for Winchester, but you should always begin with the suggested starting load. If they produce reasonable velocity, you can work your way up carefully watching for obvious pressure signs.
The Lab

.223 Remington vs. 5.56 NATO

Dear Labby,
What are the differences between the 5.56mm NATO and .223 Remington cartridges?

There is a lot of confusion on this topic, and a lot of bad information being exchanged. Externally, the case dimensions between the SAAMI recognized .223 Remington and the military designated 5.56mm NATO are exactly the same. The two main differences are maximum pressure standards and the chamber dimensions.

Mil-Spec pressure measurements are taken just ahead of the case mouth and work out to a bit more than 62,000 psi using standard SAAMI pressure testing guidelines, which are measured further back on the case body. For comparison, SAAMI’s maximum pressure recommendations for the .223 Remington are about 12% lower at 55,000 psi.

Much more significantly, the leade/throat dimensions in the 5.56mm NATO are considerably longer than the .223 Remington, allowing it to safely chamber a number of different bullet designs. The mismatch between 5.56 NATO cartridges fired in the shorter throated .223 Remington chamber can produce unexpected pressures because the bullet is jammed into the rifling. Conversely, .223 Remington cartridges fired in a 5.56mm NATO chamber may produce lower-than-expected pressures and velocity because of the longer leade.
The Lab

Silhouette Lead Bullet Data for the 45 ACP

There is no listed 230gr., LRN, 45ACP loading data for Silhouette. Reading some of the forums, Silhouette is highly recommended for 45 ACP. Do you have any reloading data that you can share for this load?
Thanks in advance for your consideration. BTW, I am overwhelmed by what a good powder True Blue is, just amazing!

Sihouette would be a great powder in the 45 ACP using 230 grain lead RN bullets. It just wasn’t tested. The lab has scheduled testing using several different manufacturer’s lead bullets to fill this gap. In the meantime, the starting loads for 230 gr. plated RN bullet data can be safely used for lead round nose as well.
The Lab

Tac in the AR-10

Any TAC RAMSHOT load data on the .308 Win for use in an AR-10. Currently using it for .223 in all of my long range competition rounds. Like to use it in my .308 for the same purpose. GREAT POWDER

Ramshot Tac has a very good burn rate for both the AR-10 and M1A/M14 rifles. Any load provided in our guide that is suitable by twist rate and COL is appropriate for either rifle system.
The Lab

Changes in Older Load Data

I am new to reloading and am currently loading for a 270WSM. I am loading up 110gr Barnes TTSX using Accurate 4350. I loaded 3 rounds each of 68gr, 67.5gr, and 67gr. I am basing these loads off your 1/27/2014 updates, using the same grains as the 110gr Hornady V-Max. My question is why was there an increase in the start load and max load grains for bullets such as the 100gr Hornady from the older data?

The newer data for the 100 grain Hornady Spire Point was developed from this latest round of testing. The older data proved to be under pressure when tested in our lab and was adjusted to provide higher pressures and better velocity.
The Lab

Pressure Differences Between Plated and Jacketed Bullets

The Rem 95gr FMJ is working very well with the high end load of 3.7gr.
Less then that was jamming. I asked below on the Berry 100gr bullet RN, but these are also copper plated or what appears to be as a FMJ not bare lead. Since it is not the bare lead RN, should I still use the 3.7 gr for the 100gr bullet? I’m thinking the 3.2 will be too light and jam.
I’m using an auto loading disk system to dispense the powder so I don’t have much room to play. Basically would the 3.7gr of powder be ok with the 100gr rn FMJ?
Please let me know your thoughts…
Your help is greatly appreciated.

All other things being equal, plated bullets develop pressure faster than copper jackets. Because their plating is relatively thin, they can tend toward lead bullet pressures. In this case, the Berry’s 100 grain bullet would have been over pressure in our test barrel using a 3.7 gr. charge.
The Lab

175 gr .308 Winchester Loads Using LT-32

Concerning the .308 Winchester, I noticed that the load data stopped at the 168 SMK for the LT-32 powder. Is there further data for the 175 gr. SMK or the 178 AMAX?

We just tested the 175 gr. Berger BTTLR bullet using LT-32 in the.308 Winchester. This information should give you a starting point with the other match bullets. Here is the data:

Accurate LT-32         Starting       FPS       Max     FPS   PSI        COL      Percent Fill
175gr  BERGER         34.6           2,278     38.4    2,505  61,609   2.810    94.20%

Magnum Small Pistol Primers in Non-Magnums

I have small magnum pistol primers. Can these primers be used with pistol loads calling for the non-magnum type by reducing the powder weight by a certain or trial percentage?

The short answer is yes, you can use magnum priming in non-magnum pistol cartridges, but there is no simple equation that defines powder reduction for the primer’s extra brisance. Substituting any component in a known handload requires going back to the starting load and working up carefully while watching for pressure signs. It is possible, especially in some very high pressure, small capacity cases (9mm Parabellum leaps to mind) that pressure signs may occur even with the starting loads and magnum priming. In all instances, velocity will provide the best indicator of pressure. If the velocity of your test load is greater than the published maximum, compensating for barrel length differences, then the load is probably above SAAMI guidelines for pressure and should be reduced.

The Lab

Handloading the 5.7X28

I need some honest load recommendations for a 5.7 FN: primers, powders and bullets. Seems cases are limited in brands. Any help will be appreciated.

The 5.7X28 is an extremely finicky cartridge, especially when reloading fired cases. The case only has about 10 grains of useable case capacity and is designed to work at pressures up to about 50,000 psi. Changes of a few tenths of a grain can produce unexpected pressures.

Reloading fired cases adds two new issues. The case head and web are small and tend to allow the primer pockets to swell prematurely. When reloading, discard any cases that exhibit little primer tension. The amount of pressure required to resize 5.7 cases is very great compared to most cartridges. Make sure enough lube is used; a stuck 5.7 case is a bad experience.

We have handloading data available in our new 5.0 Reloading Guide. All of our data is based off of FN cases. The Hornady bullets in 35 and 40 grains were great perfomers. When working up loads, work up in .1 grain increments. This is a very tricky little cartridge.

The Lab

7mm Weatherby Data

I do not find any info in your gude for the 7mm Weatherby round. Any plans of adding it?

We do have the 7mm Weatherby scheduled for testing. It should be completed later this year. Once complete, it will be posted on our downloadable “Latest Updates” section located on the upper left hand side of the screen. Clicking there will show all of the data our lab has released since our 5.0 Reloading Guide was published in October, 2013.

The Lab

Can’t find .223 Remington Data

Why can’t I find load data for the .223?

We have quite a lot of loading data for the .223 Remington, as well as for the .223 Winchester Super Short Magnum. Both can be found in the downloadable version of our 5.0 Guide.

The Lab

Finding Powder

Where can I get some AA7?

When handloaders can’t find powder locally, I recommend . This site monitors store inventories and updates frequently. It is a good bet.

The Lab

Loading with an Older Powder

I have Accurate Arms powder that is a few years old. It is MR 223. Is that the same as Accurate 2230?

It is definitely an older powder, but if it has been stored well, you can load with it using Accurate 2230 data.

The Lab

Charge Volume

When I fill a volume measuring tube with 120 grains of Blackhorn 209, I can tap the tube and compact the powder and create space for an additional 5-10 grains. Should I stop at the original measure or compact the load and maximize the powder in the loader.

Loading by volume instead of weighed grains can be a bit confusing. Black powder and black powder substitutes are traditionally measured by volume, simply filling up measuring device of a known size. It should be measured loosely. Unlike smokeless powder, small charge variations make almost no difference in pressure and velocity. With Blackhorn, more precise measurements can be made by weighing the powder on a scale. The conversion from volumetric to weighed grains for Blackhorn is .7, so 100 grains by volume equals 70 grains weighed on a scale.

The Lab

LT32 in a 6mm BRDX

I am wanting to try LT-32 in a 6mm BRDX with 100 grain flat base match bullets. Do you have any suggestions for starting loads?

I think LT-32 is going to be too fast for good performance in your 6mm BRDX. A slower powder like A2495 would be a better choice.

The Lab

What is +P

In your newest reloading data, you have listed “45 Auto (ACP) +P, What is +P?

Some cartridges have a standard pressure range and a second, higher pressure range that is also recognized to be safe in pistols rated to those pressures.  Both ranges are set by SAAMI.   +P is most commonly associated with the 9mm Parabellum and .38 Special cartridges. 

Cartridge       Standard SAAMI Pressure Max         +P SAAMI Pressure Max

.38 Special       17,000 PSI                                            20,000 PSI

9mm Para        35,000 PSI                                            38,500 PSI

.45 ACP           21,000 PSI                                            23,000   PSI


Extrapolating Load Data

Is there an EASY way to make equivalent loads from my Bullseye Specs to using No. 2?

With a chronograph and our Accurate #2 load data, it isn’t hard to make comparable loads if you intend to make cartridges that have similar external ballistics.  There isn’t a way to convert grains of Bullesye to grains of Accurate #2 in a cartridge.  There are too many internal ballistic variables for a conversion to work safely and reliably. 

Finding Powder

It is very hard to find Reloader 15

I’m surprised how often we get questions about Alliant products.  Accurate and Alliant’s “A” probably makes for some confusion.  No matter the manufacturer, powder demand is simply higher than the industry’s ability to supply.  There is no secret government mandate or oppression that is keeping us from supplying canister powders.  We sold more powder last year than we have in the history of our company and this year is on track to eclipse last year’s record.  We are doing our best to get powder out to the public.

Older IMR Powder data

Accurate 4475, can it be used in .223?

IMR 4475 was an original military propellant for the .223 Remington, but we are not aware of an Accurate 4475 canister product.  There certainly hasn’t been one since the Western Powders acquired Accurate in 2004.  We do have A5744, but data cannot safely be interchanged between it and the IMR product.  Data for the .223 Remington using A5744 can be found in our new 5.0 guide, which is available for downloading on this site.

A8700 Data

 Where can I find load data for AA8700?

A8700 was a very slow powder offered by the original Accurate Arms Company.  It is most at home in the .50 BMG.  The best source for loading data is the Accurate Smokeless Powders Loading Guide, Number 2.  Although it is out of print, it is still may be found online at reasonable prices.

Older Posts

Tumbling Loaded Ammunition

Dear Sir,  In reloading ammunition at my home, is it a safe practice to use a tumbler / Vibrator with reloaded ammunition with Accurate powder after the rounds have been loaded?

 It isn’t a recommended practice.  The geometry of each grain of powder plays an important role in the overall burn rate.  As the individual grains rub against each other, they can wear away deterrents or change geometry which may cause higher than expected pressures.

Wild Boar In .243 Win.

Can you confirm that Ramshot Wild Boar is not usable with the caliber .243 W. because the table reloading takes the majority of the class except the .243.

First, Ramshot Wild Boar is not available in the United States, although it shares load data with Accurate 2520.  By class, I believe that our questioner is referring to cartridges using the same parent case.  In this case, the class of cartridges would include the .22 CHeetah, .243 Win., .260 Rem., 7mm-08 Rem., .308 Win., .338 Federal and the .358 Win.  They are all based on the .308 Winchester case.

It makes sense that a good powder in the parent case should work well across the board considering the main difference is a change in the neck diameter, but this is not the case.  As a general rule, necking down the parent case requires a slower powder and necking it up requires a faster one. So, the.243 Win. requires slower powder than the .358 Win.

Where is Accurate 2520

I haven’t seen A2520 for over a year. When will there be some?

I like A2520, too.  I just don’t know when you will see it again in your area.  The best advice I have is to watch which is a site that keeps track of handloading supplies for sale through a number of retailers. It is a very good resource for finding powder.

Bulk Powder Vs. Canister Products

Is it true that True Blue is the same as PCL 504?
We get this type of question quite a lot, especially since canister powders have become harder to find.  No, they are not the same powder and the data may not safely be interchanged.  There is a tremendous difference between bulk powders used by OEM’s and canister grade products.  Simply having a drum of powder with an identifiable bulk designation does not mean it meets canister pressure and velocity requirements.  Until it has been tested and certified as canister grade, no bulk powder should be trusted as safe to use with published data.    

Data Powder 2200

Is the Accurate 2200 the same as the “Data 2200” that was for sale about 10 or 12 years ago?

Yes it is. The current Accurate 2200 is a direct copy of the military surplus Accurate Data Powder 2200.

Hornady FTX in the .357 S&W Magnum

Would the same loading data for .357 mag 140 grain bullet with Accurate #5 apply for Hornady 140 gr. Flex tip bullet.  Thank you

While we haven’t tested the FTX bullets in all the calibers, we have learned a few things.  The first is that you must follow Hornady’s recommended brass trim length which for the .357 Rem. Mag is 1.240″.  This allows use of the cannelure and keeps the over-all length from causing issues.  The FTX bullets tend to generate more pressure because of the engraving force created by its long bearing surface.  The long FTX bullet is generally seated deeper using up more case capacity, which also increases pressure.  While hard to make general statement, we suggest starting at least 1.0 grain below the XTP start load and working up from there. 

Question: Using Scoops to Measure Powder

When you were helping me the other day we decided the 3.6 gr Accurate #2.  My guestion is on the scoops i bought it shows what scoop to use for the 3.6gr with the Accurate #2 .load wich is the first scoop or the smallest. My question is, when I measure it out on the elctric scale, one scoop is less then 3.6gr.  It’s about 2.9 to 3.0.  Is that going to be ok  or should i start with the small scoop and then add to it until i get to 3.6?

The scoops are based on the VMD of the powder, which can vary from lot to lot.  Personally I do not like to use scoops for this reason.  Powder droppers are more money, but most have an adjustable thimble so you can change the volume accordingly to the powder density.  If you are going to use the scoops, find the one that drops the closest to 3.6 grains and manually adjust from there–Always check your scoops with a scale.  I am not sure if we talked before, but you can load anywhere in between the start load and max load as long as it will perform in your firearm. That being said, if a scoop drops 3.5 grains and the load works well, then by all means run with it.

The Lab


Older Powder Question

I have some Accurate 2 powder that has never been opened (was stored in a cool dry place in a sealed plastic container) that I think may be the 1st generation Accurate 2 powder, can I still use this? How do I adjust the loads? I honestly can’t afford to replace it with the new stuff (if I could find it). Any recommendations?

As long as the powder has the common ether smell and is black with no rust colored tinting, then it should be fine to use.  The Accurate #2 improved was a name change when the Accurate Arms Company had the powder produced by a different manufacturer.  As for the burn rate, Accurate #2 powder is all the same, and I recommend using our current data with your powder and start at the start loads.

The Lab

The “Same” bullet in different cartridges?

I do not understand the reason for the reduced loads in the 270 Win verse the 30-06 Win. The 270 is simply a reduced neck 30-06. The 270 neck reductions reduces useful case capacity from 4.38cc to 4.24cc or 96.8% of 30-06 capacity, but in the load data the 270 is not loaded any where near the 30-06 when using the same bullet.

This does not make since to me. The 270 should be loaded to about 96% of the same as the 30-06. For example your load data has the 150 grain SPBT using ACC 2700 powder for 30-06 at 53.1gr ~ 59.0gr with max velocity of 2932. The 270 is at 46gr ~ 51gr with max velocity of only 2840 fps. 270 powder load is 86.7% & 86.4% of the 30-06 load. Both loads are for a 1-10 twist 24” barrel.

Why is the 270 Win load not close to 96% of the 30-06 Win loads. Why would it be unsafe to use loads more in line with 96% of the 30-06 suggested loads, Am I correct that loads of Acc2700 in the 51gr~56.6gr should be safe in my 270 Winchester?

Changing the neck dimension does more than simply change the case capacity from that of the parent case.  A quick look at the pressures should begin to tell the tale.  The .30-06 Springfield case loaded with 60.5 grains of 2700 and a 150 grain Sierra SPT generates 3076 fps and 59247 psi.  This is within the SAAMI pressure limit for the .30-06 which is 60000.

 The .270 Winchester load with a 150 grain bullet loaded with 51 grains of 2700 and a 150 gr Sierra SBT generates 2840 fps and 63500 psi, which is once again within the pressure range set by SAAMI of 65000.

 It is important to understand that they are not the same bullet.  They are only the same weight.  The .308 bullet is 1.100″ in length.  The .277 caliber bullet, because it is of equal weight, must be longer.  In this case it is 1.237″.  Because of this, its bearing surface (the portion that actually engages the bore) is longer, creating more friction which in turn increases pressure. 

Bore volume plays a very significant role in the .270’s increased pressure versus the same weight .308 caliber bullet.  This is easy to understand if you consider how much easier it is to suck up water through a larger straw than a smaller one.  The smaller one takes more force to get the same amount of water.  The increased suction is an increase in pressure.  In this case, the .277 caliber bore is about 10 percent smaller than the .308 caliber bore.  Because of this, the .277 caliber bore generates more pressure than a .308 bore given the same bullet weight and velocity.

Your suggested load of 59.0 grains of 2700 will generate a bit more than 90,000 psi based on our models.  It is not a good load.

The Lab


Sometimes Magnums don’t use Magnum powders?

I bought 8 pounds of Magnum for my .458 Win.  Why can’t I find load data for this powder and cartridge?

The .458 Winchester Magnum needs faster powders to perform well.  I know this can be confusing, but magnums don’t always use slow-burning “magnum” powders.  Cartridges will give you a hint about what powder will work best simply by comparing the case mouth diameter to the cartridge diameter and length.  Imagine filling the .458 case up with fine sand and pouring it out.  It would poor out rather quickly because the case mouth is very close to the same diameter as the cartridge.  If you compare this to the .264 Winchester, which is made from the same case as the .458, the sand will pour out much more slowly.  This idea hints that the .264, an over-bore magnum, needs slower powder powders than the .458 to work up to its potential.

The Lab


Clumps in my powder?

I ordered some of your 1680 back about in December.  I just now opened it today to use it and it is full of clumps. My knowledge tells me that means moisture, am I wrong ? I just now broke the seal and it has been stored in a ammo can with desiccant packs around it and a dehumidifier running 14-16 hours a day. I can’t imagine this being my fault, if this does indicate moisture. I do absolutely everything to keep moisture away from this type of stuff as I am paranoid about it and I bought 8 lbs of it. Does this stuff just sit around in a warehouse or something. I don’t know if the pick part on the label is suppose to be red or not, but it is definitely pink, so if it was red I am wondering if I was shipped an old container.  I hope that this isn’t bad and I am stuck with it. Is this powder hydroscopic that bad ?

All powder contains a certain amount of moisture.  When the powder is stored or during shipping, it can go thru temperature cycles.  During the cycling, the moisture can be pulled to the surface and cause clumping.   Clumping can also be caused by static electricity if too dry or the powder has limited graphite content. You can break up the clumps before metering and they shouldn’t be a problem.  This will not affect the powder performance, so your product is fine.  Accurate 1680 labels are designed in Pink.  As a side note, specification for testing powder is at 70 degrees and 60% humidity.

The Lab


Do you have a question for our ballistics lab? If you have a question, please contact us.

To submit a question about Ramshot Reloading Powders, click here

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To submit a question about Blackhorn 209, click here