DOES ALL MILITARY CARTRIDGES HAVE CRIMPED PRIMERS??

[74man]

I just recently looked at some of my .30 caliber M1 Carbine ammo and noticed that they were not crimped. I have Remington, S&B, Aguila and none of it is military crimped. Most of this ammo was bought in 2010- 2013. I would like to know what other military ammo designation is not crimped and why the .30 Carbine isn't crimped? This is just for my info. Guess I have found out my answer with a google search.

Dec 28, 2016 — The standard GI 30 caliber 110 gr bullet for the 30 Carbine doesn't have any crimping groove on the bullet and military issue Carbine ball ammo is not crimped.

 

[Sudden Thunder]

Crimping the cartridge case neck on bullets would most likely cause headspacing issues on .30 carbine, so they are not crimped.
(Same with .45acp or .9mm)

Crimping in the Primers is whole ‘nother thing!

 

[GRIZ22]

Most specs for military ammo requires the primer to be crimped. This is to make the ammo waterproof. 9mm NATO requires crimped primers. I'm not sure of the rest.

 

[JO JO]

some of my .30 caliber M1 Carbine ammo and noticed that they were not crimped.

did they have the NATO cross on the headstamp ?
The purpose of the military crimp is to prevent the primer from backing out and falling into the fire control group of a weapon during full auto fire , but I have found crimps on non NATO ammo as well
even if you have a weapon that is a military caliber if you buy ammo for it that is commercially made without the NATO cross there is a good chance its will not be crimped

just reread your post you are asking about the bullet to case crimp my bad

 

[Bcwitt]

30 carbine uses a taper crimp, like any auto pistol round. Im not aware of any brass cased militery ammo that dosent use a crimped primer.

 

[Carl N. Brown]

I believe the Lake City Arsenal .30 Carbine ammo I used had crimped primers. $6 for a box of 50. 20 years ago.

The PPU, Winchester, Remington, Armscor .30 Carbine ammo I have now does not have crimped prime

 

[Conelrad]

The last thing a soldier needs is a jam from a popped primer.

Especially in an autoloader action.

 

[Charlie98]

Most specs for military ammo requires the primer to be crimped. This is to make the ammo waterproof.

No, the crimped primer is to keep the primer from backing out and jamming the action. Making the ammo water resistant requires use of a sealant around the primer/primer pocket.

 

[1KPerDay]

Most specs for military ammo requires the primer to be crimped. This is to make the ammo waterproof.

Hmmm haven't heard that one...

 

[lightman]

Every case that I have seen with the Nato cross on it has had crimped primers. A lot of the cheaper lines of ammo also have crimped primers for whatever reason. Some Federal, Remington, Winchester and even Norma sometimes has crimped primers.

Its been my understanding that Nato ammo is crimped to keep the primer from backing out when fired in weapons with sloppy chambers or excessive headspace. I haven't heard that its for waterproofing. I thought thats what the sealer thats around the primer and bullet was for.

 

[1-cavediver]

I have never encountered a crimped primer in NATO 9x19 and I’ve reloaded a lot of them. Every NATO 5.56 and 7.62 x51 had a crimped primer. Even some commercial .223 and .308 have crimped primers. I swage the primer pockets on every .223, 5.56, .308 and 7.62 to make my reloading life easier.

 

[FLIGHT762]

Some Winchester and Federal 9MM has crimped primers. I just reloaded some of those cases.

 

[mdi]

IIRC; all my 9mm NATO brass, the ones with the NATO cross in a circle all have had crimped primers. Also all my other military brass (some even prior to NATO) have had primer crimps, most annular and some stake crimped (HXP Greek surplus 30-06).

 

[GRIZ22]

No, the crimped primer is to keep the primer from backing out and jamming the action. Making the ammo water resistant requires use of a sealant around the primer/primer pocket.

Yes, you are correct.

 

[Slamfire]

Some weapon systems, the feed cycle is so fast, an uncrimped primer will actually slide within the pocket during the feed cycle.

Eugene Stoner mentions this in the 21st minute of this video. Either the primer moved back against the bolt face and ignited, or it moved forward and ignited, before the bolt closed. Might have been both types of failures.

 

[jtv3062]

I see the correction.

 

[Scout21]

I believe Lake City LR .308 brass does not utilize a crimp. That's the only one I can think of with my very limited knowledge of the subject.