I had a minor problem with my KRB firing pin not striking the primer fully. The problem was after about 20-25 shots blow back residue from the primers in the area shown in red. I dropped it out, gave it a shot of Remington Shotgun Cleaner, shook it off, and sprayed some Rem Oil of the trigger assembly, shook it off and put everything back togeather. Never had anymore problems the rest of the day. I think my problem was the crud buildup after shooting so many times. Design flaw?? Maybe but it's not enough of a bother to send it to Knight. Anygun will have problems if it's not kept clean.