Okay, I put my new 7.62 upper on my RRA lower and loaded 1 Wolf 7.62 round in the Colt 7.62 AR-15 magazine. It fired fine and ejected the shell. I cleaned the barrel and did it again; fired fine and ejected the shell. I cleaned the barrel again and repeated - same thing - fired and ejected fine. However, now on the fourth time, I loaded one bullet like before and fired... nothing. I removed the mag, and pulled back on the charging handle which ejected the unfired bullet. I looked at it and could see that the firing pin hit perfectly in the middle with what should have been enough force to fire the round, so I chalked it up to a bad round. I loaded one more round - same thing happened. I decided it could be two bad ones in a row, but not three, so I loaded one more up... same thing: nothing. I examined all 3 failures with the three spent cases and all looked fine. So I loaded the next bullet in the box into my Maadi and it fired just fine. I then put the next round into the 7.62 AR again - it didn't fire. Grrrrr...
I am fairly new to AR's in general (built 5 of them and all worked fine). The 7.62 is a DPMS facotry complete upper (DPMS built it) and is headspaced properly.
Does anyone have any ideas on this, or was I just plain unlucky with the rounds I put into the AR?