I'm using CCI LR primers in 308 Winchester Lapua brass, 175 gr Matchking and 45.5 gr. Hodgdon CFE223 powder. I'm getting on average 1 miss fire per 50 is a guess. Primers aren't old. 1½ years at most from Midway. I'm suspecting the density of the powder? Not sure. It is agitating when it happens. Around 75% of the time a second strike will ignite them. Savage m10 and the strikes look to be relatively hard. I ordered a new firing pin assembly and it's in. I will be changing it out this afternoon, if the creeks don't rise and the good Lord is willing.