Primer hardness

[cdet69]

What would the general hardness for primers be? Hardest to lowest? I would like to use these in a rifle that needs milspec primers. I tried doing a search but did not get anywhere. Thanks.

[USSR]

So, what is the rifle that you say "needs milspec primers"?

Don

[fouronesix]

What would the general hardness for primers be? Hardest to lowest? I would like to use these in a rifle that needs milspec primers. I tried doing a search but did not get anywhere. Thanks.

One problem is that manufacturing of primers changes and will likely continue to. So- within standard commercially available primers, Brand X may test as the hardest one year, then Brand Y will test as the hardest a couple of years later... and so on.

I know CCI makes commercially available large and small rifle primers to "mil-spec" hardness. I use the CCI 34 in my Garand (I put up a pretty good supply well before the latest primer crunch). Some don't bother worrying about slam fires using any primer. I don't worry about slam fires because I use the CCI 34s, keep my Garand in top form and carefully handload ammo for it.

[Charley]

I use CCI 34s in 7.5x54, for a MAS 49/56. It will slamfire with any commercial primer brand I've tried in it. Doesn't happen with the #34s.

[perotter]

It isn't the hardness of the primer that prevents the slamfire, it is the metal thickness of the cup. That spec can be found.

[fouronesix]

Thickness is just one of the primary variables that affect sensitivity. After all, sensitivity is the factor of interest for this discussion and the issue of slam fire as it relates to the primer. Cup thickness, cup hardness and distance from cup to anvil ALL affect sensitivity.

Here's a pretty good write up on the subject.

http://www.sksboards.com/smf/index.p...c=56422.0;wap2

[Reloader06]

416

Interesting read. Thanks for the link.

Matt

[30calflash]

I use CCI 34s in 7.5x54, for a MAS 49/56. It will slamfire with any commercial primer brand I've tried in it. Doesn't happen with the #34s.

Years back I worked at an LGS when the last primer shortage occurred. (Mid 90's) One of the first available primers that arrived were the CCI#34's. Not having ever heard of them I called CCI and asked about them.

The tech said they were the LR mag primer with a shorter anvil to make them less sensitive. Recommended for service rifles where slam fires were a potential problem. When they were sold to shooters and results came back they worked as well as the former primer in their match loads. This was in match M1A's, fired by master level shooters.

[USSR]

Years back I worked at an LGS when the last primer shortage occurred. (Mid 90's) One of the first available primers that arrived were the CCI#34's. Not having ever heard of them I called CCI and asked about them.

The tech said they were the LR mag primer with a shorter anvil to make them less sensitive. Recommended for service rifles where slam fires were a potential problem. When they were sold to shooters and results came back they worked as well as the former primer in their match loads. This was in match M1A's, fired by master level shooters.

Hmm, this begs the question, why on earth would master lever shooters with match M1A's be using magnum primers in the first place? FWIW, the CCI #34's do not have a good reputation for low ES and SD numbers, which is what you want when used in Match loads.

Don

[30calflash]

Hmm, this begs the question, why on earth would master lever shooters with match M1A's be using magnum primers in the first place? FWIW, the CCI #34's do not have a good reputation for low ES and SD numbers, which is what you want when used in Match loads.

Don

It's not advertised as a mag primer, a military primer is the term used. From CCI:

http://www.cci-ammunition.com/produc...ers.aspx?id=30

For tests by the NRA years ago, when 308 was king in high power, CCI mag primers were no hotter than Win std primers. Win and Fed 210's were the go to primer for a lot of folks.

And, it was during a primer shortage. May not have been first choice but it worked well and got the job done. I never heard complaints about them and some folks requested them later, IIRC.

[perotter]

Thickness is just one of the primary variables that affect sensitivity. After all, sensitivity is the factor of interest for this discussion and the issue of slam fire as it relates to the primer. Cup thickness, cup hardness and distance from cup to anvil ALL affect sensitivity.

Here's a pretty good write up on the subject.

http://www.sksboards.com/smf/index.p...c=56422.0;wap2

The compound that is used also affects sensitivity. This is really what dictates everything else that is done to alter the sensitivity of a primer to the given spec.

[fryboy]

here's some more reading

http://www.jamescalhoon.com/primers_and_pressure.php

[Reloader06]

Thanks Fryboy. Interesting findings. Goes well with my observations, and other reading.

Matt