I spent 30 years in the Army as a firearms instructor for 25 of them either full time or as an additional duty. I shot competitively using M-14s and never had or heard of a slam fire from them or a M-1A. If there was ever a reason for a slam fire, it would have to be that the rifles were not maintained, cleaned properly and the firing pin stuck, which was not a regular occurrence and almost unheard of. Over my years in the Army I had fired over 250,000 rounds of 7.62 MM ammo, either Lake City Match or Machine Gun Ball in training and matches. I never had a slam fire or for that matter a misfire or hang fire. Once moving to combat match shooting with the M16 I did experience a few misfires out of the M193 55 gr ammo but never any problems with the M855 62 gr. I have been reloading since 1971 or 1972, hard to remember exact dates. The only primers I ever had an issue with were CCI small pistol back in the 70's. Otherwise any and all primers seemed to perform to expectation. These days I much prefer Federal for both pistol and rifle in both small and large configuration using magnum versions in both for probably the last 5 or 6 years. All of my loads are now based on magnum primers and they work well no matter what. The bottom line is, don't be afraid to use what you have or what is available. You might have to modify your loads slightly but well worth the effort.
