CCI No. 41 primers for 5.56 ammunition used in .30 US car loads?

[barnetmill]

I am planning to load up some M1 carbine ammo and going through my primer stocks for small rifle primers I have some "CCI No. 41 primers for 5.56 ammunition". Are these fine for the .30 US Carbine loads with H110 powder. They are supposed to be harder primers to prevent slam fires. I also have some No. 6 1/2 Remington small rifle primers which might also be used. These likely are not military spec. I likely have some much older primers elsewhere in storage that I can look at also.

Loads from the Hodgdon manual will be 14.5 grains of H110 with 110 grain jacketed bullets. Some FMJ and some soft point intended for the M1 Carbine. The cases are mainly GI.

 

[ArchAngelCD]

DO NOT use the Remington 6 1/2 primers. Remington says they are only for cartridges like the .22 Hornet.

I see no reason not to use the CCI NATO primers in your 30 Carbine. They are a magnum class primer so if you're at the top of the pressure curve drop back on the powder charge just a bit since the Hodgdon data was developed with a standard SRP.

 

[barnetmill]

The pressure is not an issue since the .30 us carbine round with these loads is supposed generate 32,000 to 36,500 CUP. This is in magnum pistol range for pressure and the powder charge are about the same. The .22 hornet may be in that pressure range the powder H110 is commonly used in .357 and .44 mag loads. For the .22 hornet from the same source I get 42,300 CUP with max load for H110 and 50 grain bullet. Primer is
Primer: Winchester SR, Small Rifle
I went back to the ck for the .30 carbine and they recommend the
Primer: CCI 400, Small Rifle. Is this primer similar to or different from the Rem 6 1/2.

 

[FROGO207]

I agree the REM 6 1/2 primers are softer and made for the .22 Hornet and other lower pressure rifle rounds in general. I have used them successfully in 38 SPL reloads in a couple 357 wheel guns as well when I ran short of SPP. As long as the firing pin strike will set off the harder CCI NATO primers in whatever firearm you use them in then I also agree you are good to go.

 

[Laphroaig]

I agree with frog that if your firing pin will set of the CCI 41's they should do fine.

As for the Rem 6 1/2's, 30 carbine and 22 Hornet generate very similar chamber pressures. I'd at least give the rems a try before I'd totally rule them out. Your 14.5 gr. load is below the 15.0 gr. max (which was the original GI load if I recall).

Laphroaig

 

[barnetmill]

Thanks all. I found the best answer on the CMP forum and MI garands and carbines are what they are about.

Remington ran Lake City Army Ammunition plant from 1941 until 1985 and during that time the CCI 41 and 34 mil-spec had not been invented yet. Remington during that time loaded .30 carbine ammunition at Lake City with the 6 1/2 primer in the .30 carbine ammunition.

Bottom line, Remington from 1941 till 1985 followed by Winchester from 1985 till 2001 didn't use thicker primer cups when they ran Lake City. And both the M14 and M16 rifles had the firing pins lightened to prevent slamfires after field testing. In both cases the slamfires happened when single loading a round in the chamber "without" the magazine in the rifles to slow down bolt velocity.

Below, any primer with a cup thickness of .025 is good enough to be used in a semiauto rifle with a free floating firing pin. http://forums.thecmp.org/showthread.php?t=47663&page=3

 

[ArchAngelCD]

And what was your conclusion from what is in the CMP post from 2009? What are your conclusions?

"Primer: CCI 400, Small Rifle. Is this primer similar to or different from the Rem 6 1/2."

It's not my opinion the Rem 6 1/2 primer is not up to normal rifle primer standards, it comes directly from Remington. Truthfully I have no idea why they are still being produced. No, they are not equal to the CCI400 primers. The CCI SRP are much better suited for most applications.

Normally all SRP would be similar and interchangeable as would SRM primers. Only the Rem 6 1/2 primers are meant for low pressure rifle cartridges according to Remington.

 

[GooseGestapo]

The CMP advice is spot on. I'm over at the CMP forum too, and Shoot CMP matches.
I use Winchester, CCI, and the heavier #34's in my M1 Garand ammo interchangeably, but I DONT DROP THE BOLT ON A CHAMBERED ROUND. I've never experienced a slam fire myself, but have witnessed a few. ALL were from bolts dropped on chambered rounds WITHOUT, magazine follower friction. I use 2-shot and 8shot clips in the Garands, and inserted magazine in the Carbine.
The only 61/2's I've ever had were/are used to load .327Federals for my S-7. CCI SRP for the Match AR and Carbine.

Added, I have seen pin marks on my .223 from AR, as I use a Satern single shot adapter for the AR. Hence the CCI 400's or #41's.

 

[ArchAngelCD]

Added, I have seen pin marks on my .223 from AR, as I use a Satern single shot adapter for the AR. Hence the CCI 400's or #41's.

When the CCI#41 primers are not available I try to buy CCI-450 primers. Both are magnum class primers and the 450s are almost as resilient as the #41 primers.

I must admit, I have used CCI-400 primers in AR ammo without incident. If the #41 primers are not available I would rather use CCI-450 primers if I have a choice over the CCI-400 primers but I will use all three plus Remington 7 1/2 primers.

 

[barnetmill]

And what was your conclusion from what is in the CMP post from 2009? What are your conclusions?

"Primer: CCI 400, Small Rifle. Is this primer similar to or different from the Rem 6 1/2."

It's not my opinion the Rem 6 1/2 primer is not up to normal rifle primer standards, it comes directly from Remington. Truthfully I have no idea why they are still being produced. No, they are not equal to the CCI400 primers. The CCI SRP are much better suited for most applications.

Normally all SRP would be similar and interchangeable as would SRM primers. Only the Rem 6 1/2 primers are meant for low pressure rifle cartridges according to Remington.

My conclusions are that for the 'sub caliber' .30 us m1 carbine that the 6 1/2 remington primers is the one to use. I will save my harder 41 CCI SR primers for 5.56 loads. People here keep talking about magnum primers and high pressure rounds. Does not apply to the .30 us car round. I do not slam bolts on chambered rounds regardless of the primer. Originally magnum primers were meant for magnum rifles with large charges of slow burning powder. People were loading moderate charges of 4895 in 30-06 M1 garands for years getting accurate results before anyone heard of a magnum primer.

edit please excuse my delay in responding.

 

[Rule3]

I am always intrigued by the discussions over regular SRP and CCI 41 primers. Before the 41 primers where advertised, promoted and marketed as the primer to use for 5.56, what primers where used by the millions?? But what about "tactical or Zombie" use??

CCI 41 primers are thicker not harder.

Hornady, Speer, Lyman manuals as does Hodgdon online all show the use of "regular SRP" in 5.56 loads

As to Remington primers? I have no idea, never used them.

 

[Swampman]

I had a high percentage of misfires when working up a .30 Carbine load for my old Plainfield with CCI #41 primers.

I switched to Federal 205's and haven't had any problems. I am careful to only feed from the magazine and I keep my bolt clean with no oil or grease in the firing pin channel.

I wouldn't have any reservations about using Remington 6 1/2's in the .30 Carbine if that's what I had on hand.