CCI No.34 Millitary LR Primers?

Milspec primers are mag strength for reliable ignition

They have a thicker cup to help prevent slamfires as well as a stronger brissence (igniton spark). So they might seat a bit harder than you are used to. I can't tell the difference seating both types using my older Lee round style hand primer. As long as you start at 10% below max and work up your load they should end up being about the same. Might be a couple tenths lower charge for the same accuracy or might be the same. I would still work up again at least minimally for safety.

AJC1 said:

Milspec primers are mag strength for reliable ignition

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That is correct. They are no "hotter" than a Magnum primer.

I have used some #34 primers around 20 years ago. They worked like other large rifle primers in terms of loading and shooting. I understand they are primarily 'harder' as Frogo207 says. Still no observable difference.

I just ran into pressure with them today. They are not a direct swap if your load is on the hot side. I have never run into pressure where the seal between the primer and the brass was broken and left a gray ring. Brass also had a swipe. I swapped from CCI200s to 34s. Should have reworked the load.

I’ve used them in 308 and 30-30 loads. They work fine. All my 308 loads have been with them. I normally use Winchester LRP for 30-30 but tried a few to see if they’d work.

DMW1116 said:

I’ve used them in 308 and 30-30 loads. They work fine. All my 308 loads have been with them. I normally use Winchester LRP for 30-30 but tried a few to see if they’d work.

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I ran a test to compare velocities of a series of primers, including CCI #34 with my standard 30-06 match load of 47.0 grs IMR 4895. I use this charge with 168 match or 175 match, surely the heavier bullet produces more pressure, but given this is a mild load, I do not see pressure issues.

While the #34 is considered a magnum primer, its influence on velocity is not readily distinguishable from “standard primers”. But then, my load should be from 40,000 to 45,000 psia, as this target load is based on velocities and pressures of M1 Garand loads. Which are mild compared to most of the hot rod loads out there.

Winchester primers were labled “magnum and standard”, and the CCI #34 produces similar velocities, so it is reasonable to assume pressures are similar. But then, without a pressure gauge, this is only a guess.

I have lots of 174 FMJBT's, five gallon buckets of LC match brass, so I used those and all the primers I have rolling around the reloading room. Any load I have developed with 174’s is perfectly safe with 168 match bullets.

I do not recommend the use of Federals in Garands, Federals are the most slamfiring primers around, so I am not publishing any federal primer data in my Garand, because someone may think it might be an endorsement of use.

Tula 7.62 primers were advertised by Graf as equivalent to CCI #34 primers. CCI #34 primers are advertised as being “mil spec” primers by CCI. Mil Spec primers are the only appropriate primers to use in Garands and M1a’s as they are less sensitive than commercial primers and greatly reduce the risk of an out of battery slamfire.


the #34 shoots well in all my centerfire rifles.












Each primer lot varies in sensitivity, intensity, etc, because primer cake is mixture of components, all of which have allowable plus of minus percentages, and of course, each ingredient varies in purity. If your data is maximum loads, then regardless of primer type or lot, you are going to have to re run your load development or you run the risk of pierced, leaking, or blown primers. Incidentally, if you change anything, like case, powder lot, bullet, then similar overpressure indications may appear. I know they have for me and for others. A shooting bud of mine never took into account the new Kreiger barrel on his rifle when he first used CCI #34 primers and encountered pressure problems. He blamed the primer, because he was assuming a barrel was a barrel was a barrel. Not so, Kreiger barrels are tight and if Bud had been running his old loads, he would have blown his old primers with his old loads in his new Kreiger barrel. Instead, he bad mouthed CCI #34 primers on the web, until such time, he figured out, he should have kept his mouth shut. But by then, the impression he left on the web stayed around for years.

Slamfire,
I concur with every word you wrote. This was all me. Too many variables in my failure. Different brass. Too much neck tension. And this load was already on the verge of being max. It was only within published data in one source out of the many I checked.
34s are great primers. Don’t take shortcuts with any component swap.

As a newb, I'm normally content to ask questions or offer opinion on non-technical issues, vs. advice. Having said that, a few months back, I picked up 500 pieces of Lake City pull down brass, both for the brass and the primer they held, which is said to be these CCI 34 primers. Seeking advice on how to load these, one thing that turned up was the "why" of the magnum primer in Lake City ammo destined for military use. It is said it was to offer reliable ignition at sub-zero temps of the double base spherical type powders (LIke BL-C 2) that was or is used in this ammo.

But advice given was to reduce starting loads in this LC pull down brass by 2 full grains.....one for the primer, another for the smaller capacity Lake City case. So far, so good.

But as for these LC primers, my plan was to fire them, then replace them with standard primers for subsequent reloads. But that now has me thinking......if I go to the trouble to work up decent loads for these, what harm could come of simply replacing these spent primers with more CCI 34 primers? They are available and I'm still padding my stash. I'm close enough to Midway I can pick them up at the door vs. paying hazmat and shipping.

I see it as being like burning 91 octane ethanol free gas in my lawnmower. Not needed, and more expensive, but does no harm.

On the other hand, if I'm handicapping myself and could do better with standard primers, then that is what I should do.

JussRight said:

I do have 8lbs of BLC(2) yet untouched. My platform is AR10 aero. Criticism is welcomed.. thank you

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BL-C(2) is a classic .308 powder, I've not really bothered with it because it has been described to me as 'quite blasty' when compared to something like IMR4895, et al. Given that I shoot it in a 16" braked barrel, I don't need blasty for sure... but it would be a reasonable choice for a gas operated AR-10, all else being equal.

Howa 9700 said:

But as for these LC primers, my plan was to fire them, then replace them with standard primers for subsequent reloads. But that now has me thinking......if I go to the trouble to work up decent loads for these, what harm could come of simply replacing these spent primers with more CCI 34 primers? They are available and I'm still padding my stash. I'm close enough to Midway I can pick them up at the door vs. paying hazmat and shipping.

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#34's aren't a bad choice... they are not a match type primer, however, so if you are going for accuracy, that would not be my first choice. If you are able to get them vs other primers, at a comparable price, then I'd do that. I load for different .308 rifles, but I only use the #34's for my M1a and M1 Garand, as appropriate.