410 GNR

I have a difficulty getting my 410GNR loads to fire without cratered primers and or primer flow back into the firing pin hole and locking up the cylinder. I have tried loads (starting loads in Gary's manual) using W296, H110 and wc820, Winchester, Federal and CCI primers of the magnum persuasion and standard, with the Sierra 170JHP and Hornady XTP and still have not gone more than one cylinder full before a problem. I brush out the cylinder and clean it out with a dry patch before I try another change in load. The first loads I fired through it were from Andy at CPE and with all three I had the same problem. I'm using LJK-CPE 410GNR headstamped brass. I have 0 problems with 41 Mag loads in a second cylinder in this gun. Suggestions from Gary and any Misfit are greatly appreciated.