I use nothing but Federal primers for my semi-auto handguns as wel as my wheel guns. As for the AR and M1Aicon etc.. I use Federal primers with no problems at all... the only rifle I had a problem with was my HK-91.. I had 1 slam fire about 4 yrs ago.. and this was after 20yrs of loading for it and something over 20K rounds through its barrel..... but for the most part, I use CCI rifle primers.