Best primer choice(s) for .223/5.56 autoloaders?

[rtp]

I'm loading for an AUG A3, loading mainly 55gr-69gr. You can consider it a 16" 1:9 twist AR for loading purposes..

I've got a few mixed SRP I was able to get my hands on - maybe 1200 Winchester Small Rifle, and 1k of Remington 6 1/2s.

Obviously, like everyone right now, I'm keeping my eyes open for both powder and primers.

It seems likely that Tula's may become available more readily than CCIs, let alone the CCI mil-specs.

Tula/Wolf also seems to have lots of variants..can someone share what's worked for them?

I do see a fair number of loads wanting magnum primers, but it may well come down to what I can get my hands on..

Powder is at the moment a few lbs of H335 or BLC-2...hoping to find some TAC at some point this year.

How important are the magnum or mil-spec primers?

I understand this to mainly be about potential slam-fires - is it mainly about a harder primer cup, or is it also for more complete powder ignition?

What are my best options here from best to worst?

[M109R]

Any that you can find and will work right now!

[Steve RA]

Tula small rifle .223 work quite well. (KVB.223).

[rtp]

Tula small rifle .223 work quite well. (KVB.223).

Thanks, Steve.

Tula is the one driving me nuts with their part numbers - seems they have SRP, SRPM, SRP 'NATO', and SRP - 223..maybe the latter two being identical?

Is this a case where the .223s are 'most desirable,' but the SRP Magnums are also OK for autoloaders, or ?

[Old3GNR]

One solution to "slam fires" is a Titanium firing pin.

[Sig Shooter]

I have loaded about 600 rounds on a 650 press using Wolf Magnum Small rifle primers with good results.

[Steve RA]

I'd imagine all the Tula SRPs will work ok, I just like to stay with one version. I use the one with part # KVB .223.

[rtp]

Thanks, everyone. Failing CCIs becoming available, at least for Tula, I'll try to get the .223, followed by the SRMs, followed by <whatever the heck I can find> in worst case.

I'm definitely not seeking out Tula, but it seems ironically the 'Russian supply chain' may be better than our own manufactures at the moment, and they're showing up more readily..

Maybe the better question is which primers to specifically avoid for autoloaders? I've seen mention of Federal cups being soft but are there any SRPs to definitely stay away from for a .223/5.56 autoloader?

[bigedp51]

When the M16 first came out during testing there was a slamfire problem with the first Remington ammunition loaded for it with 6 1/2 primers and loading a single round in the chamber without the magazine in place. The military fix was to lighten the firing pin and switch to primers with "thicker" cups. With the magazine in place the bolt velocity is reduced by drag and feeding the cartridge into the chamber.

Any primer with a cup thickness of .025 will work fine in a AR15 rifle with its free floating firing pin.

Edited May 16, 2013 by bigedp51

[rtp]

Great diagram, thanks!

I did some additional searching in the meanwhile, and it mostly jives with what you just posted + recommendations for Wolf/Tula SRM or SR223, but advising against Remington 6 1/2s (which jives with the diagram).

[Pinecone]

From what I understand from various sources:

CCI 450 (SR Mag) and CCI #41 (SR Military) are almost the same primer. The #41 has the anvil seated a little less deep, so a bit deeper firing pin strike needed to ignite. But the same cup thickness. I load CCI 450s for my .223 loads.

The Remington 7 1/2 is the same primer as they load for military ammunition.

[Steve RA]

Think the Rem 7-1/2 is about the toughest SRP, back when all the titanium firing parts were all available they were the only SRP that would not ignite reliably for me.