I resized a bunch of brass and didn't bump the shoulder back quite far enough. They still chamber, but with a little work. I am getting great accuracy with them, probably in part to the glove like fit. Anyway, say I had one that wouldn't chamber, and I was really forcing it, if the primer wasn't as far below flush as it should be, could this cause a slam fire, possibly with the bolt only half closed?? Just a thought. I'm not like beating on the bolt to get it to close or anything, just using a little bit of elbow grease on one here and there. Your thoughts?