WW2 45 brass specs

Ike Clanton · October 11, 2023, 09:11 AM

I’ve been loading 45 ammo for suppressor use with mixed range brass for plinking. My LNL progressive jammed up a few times during priming. 9 times out of 10 it was military brass ranging from 1942-67 ish but mainly the 1940’s stuff. It seems to me the primer pockets are too shallow or possibly narrow to seat properly. Is this a normal occurrence?

Marco Califo · October 11, 2023, 09:23 AM

You already found the problem: 50+year old brass. Here is your solution:
https://www.starlinebrass.com/45-auto-brass

ballardw · October 11, 2023, 09:51 AM

Were the primer pockets swagged or trimmed before use? Perhaps need a bit more of the crimp removed before use in the LNL. I wouldn't be surprised if there were a difference in the earlier crimps than later.

**Unclenick** · October 11, 2023, 10:32 AM

Military primers are crimped to prevent them from popping out and jamming full-auto weapons. The crimps have to be either trimmed off or swaged out before primers will seat comfortably in those pockets. It certainly sounds as if you are trying to seat primers into cases from which they needed to be removed. Hard seating and high primers are commonly the result.

Tools for crimp removal vary widely in price and operating speed. For a first-timer, just chucking a wood countersink in your hand drill and touching it to each primer pocket lip can do it. How much brass you need to remove varies with the case because crimps vary a bit. You will want to try removing just a little and taking more off if that doesn't do it. Taking off too much will lead to the potential for primers to blow out at the perimeter for lack of adequate support, but you need to remove a fair amount for that to happen. Try looking at YouTube videos of primer crimp removal.

**44 AMP** · October 11, 2023, 01:24 PM

Besides the crimp, there are tolerances and things can be slightly different sizes, and that includes the primers you are using. I've had cases where CCI primers were "stiff" to seat, and Win primers seated slick as butter.

Also, while very rare today, the US did make steel cased .45acp ammo in 43. Those cases do have a slightly smaller primer pocket size than standard.

If you do have, or run across any of them, don't bother trying to reload them.
EC 43 is the one headstamp I know of. There might be others. After the run in 43, all US GI .45 ammo went back to the normal brass cases.

I've used the RCBS press mounted primer pocket swage kit. Don't like it, real PITA for me. What I do these days is simply use the case mouth chamfering tool (the one used after case trimming). The nose fits into the primer pocket and a couple of twists cuts away the crimp.

I've never had an issue with primers blowing from the "generous" crimp removal, rifle or pistol. I can see where it is possible, but I've never had it happen, and so, I don't worry about it. You should do as you think best.

Paul B. · October 11, 2023, 03:19 PM

Well, there's good news and there's bad news. As the problem or having to remove the crimp has already been covered I pass on that one.

However, when the .45 ACP was first brought out they require a special size primer. It was larger that small pistol primers but also smaller than standard large pistol primers. The only source was through the DCM on a somewhat limited basis to IIRC, only NRA member. I do remember that odd primer size though and spent many an hour trying to convert them to take normal primers. Franky, I don't recall then the changeover to standard LP came about so it may have varied dates from the different arsenals. Whether trying to convert the ones with the odd primers is worth the effort and time is up to the OP. All I can are is that it was a royal PITA!

Paul B.

**44 AMP** · October 11, 2023, 04:43 PM

I actually have a few cases marked RA 18 (1918) have loaded them with standard modern (1970s on) Large pistol primers and they fit the pockets just fine. Same with brass from WWII and the 50s, on up. Once the crimp is removed, they've always been fine for me.

There are now some ammo makers who make .45acp using small pistol primers. Personally I consider this an abomination

but its really a PITA if some of those get mixed into your regular brass and you don't notice it until you have ruined a primer. (hint, a really loud bang! is a dead give away

)

Its more likely the primer will just crush and not detonate, but its not impossible that it might.

Jim Watson · October 11, 2023, 05:45 PM

I have read of the FA .204” primer and that it was available from the DCM/NRA but don’t know when. Haven’t seen it mentioned by Phil Sharpe.

**Unclenick** · October 11, 2023, 09:18 PM

I'd forgotten about the wartime steel cases. That's funny because I remember going up into my grandparents' attic when I was ten or twelve or thereabouts, and finding a couple of boxes of them my father had probably liberated during his service. If you have these, a magnet is your friend and will separate them out right away.

The recommendation not to reload steel is a good one. We had a fellow on another board who did it, but then noticed his chamber was pitted in a ring around the back end. Steel doesn't have the malleability of brass, so it fatigues and cracks with repeated resizing. The steel is strong, so it didn't just let go, but rather had gas jets leaking out of it and gas cutting the little pits into the chamber. They look exactly like the pits that circle a Garand or M14 bolt face after it has seen enough military ammo. That is due to gas leaks around the perimeter of primers, another thing over trimming of crimps can potentially encourage.

CCI primers used to be hard to seat in general, but Allan Jones said they fixed that when they revamped their lines in 1992 to include additional deburring of the primer cups after trimming them. Primers with burrs, like the Russian KVB primers out of the Tula plant, can still be found. Those particular ones look like they were trimmed to final height on a belt sander running 80 grit paper. They seat hard, indeed.

Ike Clanton · October 11, 2023, 09:32 PM

Well I’m gonna bet it’s primer crimp. I had no idea handgun brass got crimped back then so I didn’t even bother to check the primer pockets. Now that I’m learned up I won’t make that mistake again. Easier just to toss the crimped brass in my case. Thanks guys.

Jim Watson · October 11, 2023, 11:03 PM

Quote:

I'd forgotten about the wartime steel cases.

I dropped in on my agency’s firearms instructor - we were both in the local club - and found him loading Thompson magazines with steel case ammo. “I’m going to take the new guys out and show them how to shoot the Thompson.”

**44 AMP** · October 12, 2023, 01:05 AM

Quote:

Well I’m gonna bet it’s primer crimp. I had no idea handgun brass got crimped back then so I didn’t even bother to check the primer pockets.

If you didn't do something to remove the primer pocket crimp, that probably the source of your problem.

I'm not sure if it was done earlier but by the WW I timeframe all US military small arms ammo was required to be made with crimped primer pockets, and crimped bullets and additionally, a lacquer sealant on the primer and "asphaultum gum" sealant for the bullet. This made the rounds pretty much waterproof and also kept things from being shaken loose (or even out) by vibration during transport & handling, and in the feeding mechanisms of automatic weapons.

As far as I know the order was blanket, covering all small arms service ammo, rifle and pistol. I do not know if match ammo was done that way, or not, since I've never had experience with Arsenal produced Match ammo, though many members here have, one of them could tell us if match ammo was done like that, or not.

Quote:

Easier just to toss the crimped brass in my case. Thanks guys.

Do what you think best, but I wouldn't toss perfectly usable brass when it would only take a few seconds to remove the crimp, and only needs to be done once. If you don't feel the effort is worth it, sell them, or trade them, or just give them to someone who does.

Nick_C_S · October 12, 2023, 06:57 PM

Quote:

US did make steel cased .45acp ammo in 43.

So I guess it wasn't just pennies that were made of steel in '43.

Learn something every day.

**Unclenick** · October 12, 2023, 07:20 PM

Yeah. They were out there. A lot of wartime brass was also made of Muntz metal (60:40 brass) to cut down on the copper content, copper being in short supply.

I don't think the primer crimps were done until after WW I, (based on lessons learned in that conflict), because Garand's first rifle design was a primer-actuated rifle that had to be abandoned when the military started crimping primers. Sometime in the 1920s, I think, same as case neck annealing. I've forgotten, but the dates are in Hatcher's Book of the Garand.

Paul B. · October 13, 2023, 02:39 PM

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Paul B.

October 11, 2023, 09:11 AM	#1
Ike Clanton Senior Member Join Date: August 3, 2017 Location: Oregon Posts: 120	WW2 45 brass specs I’ve been loading 45 ammo for suppressor use with mixed range brass for plinking. My LNL progressive jammed up a few times during priming. 9 times out of 10 it was military brass ranging from 1942-67 ish but mainly the 1940’s stuff. It seems to me the primer pockets are too shallow or possibly narrow to seat properly. Is this a normal occurrence?

October 11, 2023, 09:23 AM	#2
Marco Califo Senior Member Join Date: April 4, 2011 Location: LA (Greater Los Angeles Area) Posts: 2,601	You already found the problem: 50+year old brass. Here is your solution: https://www.starlinebrass.com/45-auto-brass __________________ ............

October 11, 2023, 09:51 AM	#3
ballardw Senior Member Join Date: September 19, 2008 Posts: 1,414	Were the primer pockets swagged or trimmed before use? Perhaps need a bit more of the crimp removed before use in the LNL. I wouldn't be surprised if there were a difference in the earlier crimps than later. __________________ -+-+-+-+-+-+-+-+-+-+-+-+-+-+ All data is flawed, some just less so.

October 11, 2023, 10:32 AM	#4
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Military primers are crimped to prevent them from popping out and jamming full-auto weapons. The crimps have to be either trimmed off or swaged out before primers will seat comfortably in those pockets. It certainly sounds as if you are trying to seat primers into cases from which they needed to be removed. Hard seating and high primers are commonly the result. Tools for crimp removal vary widely in price and operating speed. For a first-timer, just chucking a wood countersink in your hand drill and touching it to each primer pocket lip can do it. How much brass you need to remove varies with the case because crimps vary a bit. You will want to try removing just a little and taking more off if that doesn't do it. Taking off too much will lead to the potential for primers to blow out at the perimeter for lack of adequate support, but you need to remove a fair amount for that to happen. Try looking at YouTube videos of primer crimp removal. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

October 11, 2023, 01:24 PM	#5
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,860	Besides the crimp, there are tolerances and things can be slightly different sizes, and that includes the primers you are using. I've had cases where CCI primers were "stiff" to seat, and Win primers seated slick as butter. Also, while very rare today, the US did make steel cased .45acp ammo in 43. Those cases do have a slightly smaller primer pocket size than standard. If you do have, or run across any of them, don't bother trying to reload them. EC 43 is the one headstamp I know of. There might be others. After the run in 43, all US GI .45 ammo went back to the normal brass cases. I've used the RCBS press mounted primer pocket swage kit. Don't like it, real PITA for me. What I do these days is simply use the case mouth chamfering tool (the one used after case trimming). The nose fits into the primer pocket and a couple of twists cuts away the crimp. I've never had an issue with primers blowing from the "generous" crimp removal, rifle or pistol. I can see where it is possible, but I've never had it happen, and so, I don't worry about it. You should do as you think best. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

October 11, 2023, 03:19 PM	#6
Paul B. Senior Member Join Date: March 28, 1999 Location: Tucson, AZ Posts: 3,802	Well, there's good news and there's bad news. As the problem or having to remove the crimp has already been covered I pass on that one. However, when the .45 ACP was first brought out they require a special size primer. It was larger that small pistol primers but also smaller than standard large pistol primers. The only source was through the DCM on a somewhat limited basis to IIRC, only NRA member. I do remember that odd primer size though and spent many an hour trying to convert them to take normal primers. Franky, I don't recall then the changeover to standard LP came about so it may have varied dates from the different arsenals. Whether trying to convert the ones with the odd primers is worth the effort and time is up to the OP. All I can are is that it was a royal PITA! Paul B. __________________ COMPROMISE IS NOT AN OPTION!

October 11, 2023, 04:43 PM	#7
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,860	I actually have a few cases marked RA 18 (1918) have loaded them with standard modern (1970s on) Large pistol primers and they fit the pockets just fine. Same with brass from WWII and the 50s, on up. Once the crimp is removed, they've always been fine for me. There are now some ammo makers who make .45acp using small pistol primers. Personally I consider this an abomination but its really a PITA if some of those get mixed into your regular brass and you don't notice it until you have ruined a primer. (hint, a really loud bang! is a dead give away ) Its more likely the primer will just crush and not detonate, but its not impossible that it might. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

October 11, 2023, 05:45 PM	#8
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,545	I have read of the FA .204” primer and that it was available from the DCM/NRA but don’t know when. Haven’t seen it mentioned by Phil Sharpe.

October 11, 2023, 09:18 PM	#9
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	I'd forgotten about the wartime steel cases. That's funny because I remember going up into my grandparents' attic when I was ten or twelve or thereabouts, and finding a couple of boxes of them my father had probably liberated during his service. If you have these, a magnet is your friend and will separate them out right away. The recommendation not to reload steel is a good one. We had a fellow on another board who did it, but then noticed his chamber was pitted in a ring around the back end. Steel doesn't have the malleability of brass, so it fatigues and cracks with repeated resizing. The steel is strong, so it didn't just let go, but rather had gas jets leaking out of it and gas cutting the little pits into the chamber. They look exactly like the pits that circle a Garand or M14 bolt face after it has seen enough military ammo. That is due to gas leaks around the perimeter of primers, another thing over trimming of crimps can potentially encourage. CCI primers used to be hard to seat in general, but Allan Jones said they fixed that when they revamped their lines in 1992 to include additional deburring of the primer cups after trimming them. Primers with burrs, like the Russian KVB primers out of the Tula plant, can still be found. Those particular ones look like they were trimmed to final height on a belt sander running 80 grit paper. They seat hard, indeed. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

October 11, 2023, 09:32 PM	#10
Ike Clanton Senior Member Join Date: August 3, 2017 Location: Oregon Posts: 120	Well I’m gonna bet it’s primer crimp. I had no idea handgun brass got crimped back then so I didn’t even bother to check the primer pockets. Now that I’m learned up I won’t make that mistake again. Easier just to toss the crimped brass in my case. Thanks guys.

October 12, 2023, 07:20 PM	#14
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Yeah. They were out there. A lot of wartime brass was also made of Muntz metal (60:40 brass) to cut down on the copper content, copper being in short supply. I don't think the primer crimps were done until after WW I, (based on lessons learned in that conflict), because Garand's first rifle design was a primer-actuated rifle that had to be abandoned when the military started crimping primers. Sometime in the 1920s, I think, same as case neck annealing. I've forgotten, but the dates are in Hatcher's Book of the Garand. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

October 13, 2023, 02:39 PM	#15
Paul B. Senior Member Join Date: March 28, 1999 Location: Tucson, AZ Posts: 3,802	Oddbal primer size .45ACP Oct 25, 2014 — The brass is primed with military corrosive primers of the time. They are easily de-primed, but the primer pockets measure only .2005 inches-- ... 45 ACP \| Shooters' Forum Mar 24, 2023 .45 ACP pistol primer size & powder charge \| Shooters' Forum Apr 24, 2022 reloading 45 acp \| Shooters' Forum Sep 13, 2016 Loading 45acp with small and large primers - Shooters' Forum Aug 23, 2021 More results from forum.accurateshooter.com Paul B. __________________ COMPROMISE IS NOT AN OPTION!