Primers

[gunrestorer]

I just wanted to know why the load data from AA calls for the sm.rifle mag. primer? I have been using the standard primers in my loads and they work fine, is it because of the powders they used? I'am using IMR 8208 and Hodgden Benchmark.

[Dogue]

I believe the magnum primers are preferred both for the thicker cap and also for the more complete burn of powders, especially when you consider the small flash hole on AA/Lapua brass. I personally use CCI41's which are not technically magnums.

[capt greg]

I been using fed small rifle primers an have had no apparent issues with imr8208.. aa2520..cfe 223..

[Bwild97]

According to CCI, their Magnum primers are recommended for ball powders, and the 34's and 41's are magnum primers that meet NATO requirements.

Primer usage chart

[gunrestorer]

Thanks , Guys. I have not had any issues with the standard primers, I'am using Hornady and Wolf brass, thats all I have right now. I will be ordering some Lapua brass next week. I have found out the Wolf brass is not very good, seems to be very soft. After 2 reloads the primer pockets seem pretty loose so I just pitch it.

[stokesrj]

You would have to shoot several tens of thousands of rounds to see the problem unless you are unlucky. You see the AR bolt comes to an abrupt halt as it chambers a round. The firing pin is free to move forward and the forward inertia continues to drive it forward. The magnum primers and a few others like the CCI41 and BR4 have a thick cup that will not as easily dent. If feeding from a mag this normally isn't a problem but if a round is dropped in the chamber and the bolt released the firing pin can hit a small rifle primer with sufficient force to ignite the round. That is why Remington for instance labels their small rifle primer the 6 1/2, not for use in AR rifles. I've personally seen three slam fires, all were standard small rifle primers. If you are seating primers with a press then the danger escalates rapidly since you can't feel the primer fully seat. For this reason I seat all my primers on an RCBS bench mounted seater. A high primer just sharply increases the risk and can result in an out of battery ignition which will tear up your upper receiver and barrel extension. One of my fellow competitors had this happen just a few days ago at home in Florida, I was looking at his upper with John Holliger at the national matches this week. It appears that was the reason for the out of battery explosion.
I know this can be hard to believe, but you can see for yourself, drop a round into the chamber, release the bolt, extract the round. You will see a small indentation from the firing pin. Do this with both a standard primer and a magnum primer and you will see the indentation is much deeper with the standard primer than with the thick walled primer.
Bob

[gunrestorer]

You would have to shoot several tens of thousands of rounds to see the problem unless you are unlucky. You see the AR bolt comes to an abrupt halt as it chambers a round. The firing pin is free to move forward and the forward inertia continues to drive it forward. The magnum primers and a few others like the CCI41 and BR4 have a thick cup that will not as easily dent. If feeding from a mag this normally isn't a problem but if a round is dropped in the chamber and the bolt released the firing pin can hit a small rifle primer with sufficient force to ignite the round. That is why Remington for instance labels their small rifle primer the 6 1/2, not for use in AR rifles. I've personally seen three slam fires, all were standard small rifle primers. If you are seating primers with a press then the danger escalates rapidly since you can't feel the primer fully seat. For this reason I seat all my primers on an RCBS bench mounted seater. A high primer just sharply increases the risk and can result in an out of battery ignition which will tear up your upper receiver and barrel extension. One of my fellow competitors had this happen just a few days ago at home in Florida, I was looking at his upper with John Holliger at the national matches this week. It appears that was the reason for the out of battery explosion.
I know this can be hard to believe, but you can see for yourself, drop a round into the chamber, release the bolt, extract the round. You will see a small indentation from the firing pin. Do this with both a standard primer and a magnum primer and you will see the indentation is much deeper with the standard primer than with the thick walled primer.
Bob

Thanks for the info that is really good to know. I for sure do not want ANY of that. Thanks again.