I just boiught an AR and I picked up 1k Federal 205 Small Rifle primers. Now I'm occasionaly reading that you should avoid them in semi-autos due to their thin cups. BUT I've also read that about WSR primers but TONS of people use those in AR's. So what should I do. These are not the 205 Match primers, just standard 205's.
I had a slamfire in the AR15 with the new thinner brass colored WSR. I was shooting 200 yards standing, dropped the round in the chamber, and hit the bolt release. The round slamfired and created a divot about 15 foot in front of the firing line.
The shooter on my point laughed at me. However when we changed relays, he started his string for record, his AR slamfired and tossed a divot in the air. And he was using Federal Match primers!! Ha, Ha.
All of the AR15 slamfires that I have heard of, and the two that I have seen, occurred after a round was dropped in the chamber and the bolt release was hit.
I have never heard of an out of battery slamfire on the AR. An out of battery slamfire would be a messy event. Unlike the M1a and M1 Garand which are known to have out of battery slamfires, the AR action seems to slamfire with some lug engagement. Which is just great.
So my advice, use any primer you want in the AR15. Feed all rounds from the magazine, and as you load it, never point the thing at anything you don't want to be dead. After all, it still has a free floating firing pin and the probability of a slamfire is never zero.
For me, I am using CCI #41 "Mil Spec" primers in my match AR's. Those primers shoot outstandingly, last year at Camp Perry I shot nothing less than a 197 with them at 600 yards.
