when & on what did the Military start crimping primers ???

Magnum Wheel Man · February 18, 2013, 07:56 AM

was going through some old ammo off my shelves the other day, reboxing some 30 carbine ammo, & noted I had some LC-52 & I started wondering if this had crimped primers, then found a box of WCC-43 hmm same question...

I have a several ammo cans of older military brass to process, so curious if they ever crimped primers on the 30 carbine, & if so, when did they begin ???

did they ever make 223 without crimped primers ??? how about 30-06 ??? I'm guessing all military 308 have been crimped because they are newer ???

Rottweiler · February 18, 2013, 08:16 AM

The idea of crimping the primers in place was originally done to prevent a primer from popping out and falling into some tight little spot in a machine gun causing a nasty jam at the worst possible time. I don't know exactly when or who came up with this idea, but it has been in practice since before WWII.

That being said, the only timesI've had a primer pop out of a round was brass that had seen multiple reloadings, never an unfired or once fired case.

Magnum Wheel Man · February 18, 2013, 08:52 AM

so realistically all the 30 carbine ( because of the M-2 ) would have crimped primers ???

how about '06 ???

**44 AMP** · February 18, 2013, 09:22 AM

.30-06 has had crimped primers at least since WW I. Can't say about .30 carbine.

**Mike Irwin** · February 18, 2013, 09:28 AM

The original impetus for crimping primers was with the widescale adoption of automatic weapons.

It became really important, and you started to see widespread crimping among most nations, when aircraft armament started moving into the wings. It was impossible to clear a jam in a wing gun, so many steps were taken to reduce the possibility, including primer crimps.

I THINK the US started routinely crimping primers on just about all ammo in the 1920s.

Magnum Wheel Man · February 18, 2013, 09:33 AM

so... sounds like all my old milsurp ammo & or cases are going to have crimped primers ( good thing I have large & small primer pocket swag tools )... even though, I'm sure they never wing mounted something like an M-2 in 30 carbine

**Mike Irwin** · February 18, 2013, 09:45 AM

No, they didn't, but they did use fully auto .30 Carbines, the M2.

It became common practice, at least in the US, to start crimping everything military, probably because it didn't add any time at all to the loading process and it, again, removed one possible failure vector.

Magnum Wheel Man · February 18, 2013, 10:00 AM

so how about older cartridges ???

45-70 for gattling guns ( I assume crimp free )

the original 30 caliber rifle cartridges ( pre '06 )

the SL cartridges ( 35 & 40 )

45 acp for tommy guns... any of these ever been crimped ???

**Mike Irwin** · February 18, 2013, 10:09 AM

.45-70. No. I've never found any indication that they were at any point in their manufacture.

.30-40, again no, none of my military examples are crimped.

SL cartridges, by which I take it to mean the Winchester commercial self loading rifle cartridges. No, very few, if any, commercial cartridges were ever crimped.

.45 ACP. Yes, I believe the military used a crimp on .45 ACP starting in the late 1930s.

Magnum Wheel Man · February 18, 2013, 10:12 AM

thanks for the replys... just needed info to keep in the back of my mind, as I process my brass ( my new hobby... decapping, polishing, & getting all my brass ready to reload )... at least until I can start buying primers again...

February 18, 2013, 07:56 AM	#1
Magnum Wheel Man Senior Member Join Date: July 26, 2006 Location: Southern Minnesota Posts: 9,333	when & on what did the Military start crimping primers ??? was going through some old ammo off my shelves the other day, reboxing some 30 carbine ammo, & noted I had some LC-52 & I started wondering if this had crimped primers, then found a box of WCC-43 hmm same question... I have a several ammo cans of older military brass to process, so curious if they ever crimped primers on the 30 carbine, & if so, when did they begin ??? did they ever make 223 without crimped primers ??? how about 30-06 ??? I'm guessing all military 308 have been crimped because they are newer ??? __________________ In life you either make dust or eat dust... Last edited by Magnum Wheel Man; February 18, 2013 at 08:54 AM.

February 18, 2013, 08:16 AM	#2
Rottweiler Senior Member Join Date: January 30, 2001 Location: Texas Hill Country Posts: 391	The idea of crimping the primers in place was originally done to prevent a primer from popping out and falling into some tight little spot in a machine gun causing a nasty jam at the worst possible time. I don't know exactly when or who came up with this idea, but it has been in practice since before WWII. That being said, the only timesI've had a primer pop out of a round was brass that had seen multiple reloadings, never an unfired or once fired case. __________________ Texas - envied by lesser states since 1845

February 18, 2013, 08:52 AM	#3
Magnum Wheel Man Senior Member Join Date: July 26, 2006 Location: Southern Minnesota Posts: 9,333	so realistically all the 30 carbine ( because of the M-2 ) would have crimped primers ??? how about '06 ??? __________________ In life you either make dust or eat dust...

February 18, 2013, 09:22 AM	#4
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,820	.30-06 has had crimped primers at least since WW I. Can't say about .30 carbine. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

February 18, 2013, 09:28 AM	#5
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,382	The original impetus for crimping primers was with the widescale adoption of automatic weapons. It became really important, and you started to see widespread crimping among most nations, when aircraft armament started moving into the wings. It was impossible to clear a jam in a wing gun, so many steps were taken to reduce the possibility, including primer crimps. I THINK the US started routinely crimping primers on just about all ammo in the 1920s. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

February 18, 2013, 09:33 AM	#6
Magnum Wheel Man Senior Member Join Date: July 26, 2006 Location: Southern Minnesota Posts: 9,333	so... sounds like all my old milsurp ammo & or cases are going to have crimped primers ( good thing I have large & small primer pocket swag tools )... even though, I'm sure they never wing mounted something like an M-2 in 30 carbine __________________ In life you either make dust or eat dust...

February 18, 2013, 09:45 AM	#7
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,382	No, they didn't, but they did use fully auto .30 Carbines, the M2. It became common practice, at least in the US, to start crimping everything military, probably because it didn't add any time at all to the loading process and it, again, removed one possible failure vector. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

February 18, 2013, 10:00 AM	#8
Magnum Wheel Man Senior Member Join Date: July 26, 2006 Location: Southern Minnesota Posts: 9,333	so how about older cartridges ??? 45-70 for gattling guns ( I assume crimp free ) the original 30 caliber rifle cartridges ( pre '06 ) the SL cartridges ( 35 & 40 ) 45 acp for tommy guns... any of these ever been crimped ??? __________________ In life you either make dust or eat dust...

February 18, 2013, 10:09 AM	#9
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,382	.45-70. No. I've never found any indication that they were at any point in their manufacture. .30-40, again no, none of my military examples are crimped. SL cartridges, by which I take it to mean the Winchester commercial self loading rifle cartridges. No, very few, if any, commercial cartridges were ever crimped. .45 ACP. Yes, I believe the military used a crimp on .45 ACP starting in the late 1930s. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.

February 18, 2013, 10:12 AM	#10
Magnum Wheel Man Senior Member Join Date: July 26, 2006 Location: Southern Minnesota Posts: 9,333	thanks for the replys... just needed info to keep in the back of my mind, as I process my brass ( my new hobby... decapping, polishing, & getting all my brass ready to reload )... at least until I can start buying primers again... __________________ In life you either make dust or eat dust...