I recently loaded 20 brand new, never fired Lake City 5.56 cases using Remington 7 1/2 bench rest primers. Shot them today and had 5 misfires (out of 20 rounds) in a Savage 10 bolt gun chambered in .223 Rem. Pulled bullets and dumped powder from the 5 dud rounds and loaded the empty, primed cases into an AR-15. Four of the five primers went off. Any ideas what may be causing the misfires in the bolt gun? Am seating the primers about 0.006" below the bases of the cases and it looked like they were getting good strikes. (see attached photo below) Thanks for any suggestions.