Primers for M1 Garrand

Bob, I used a Garand in '06 and later rebarreled to 7.62, for a bunch of years (back when my hair was dark !) I used standard primers. One of the things to consider is that in the slow-fire phases, we were dumping a round in the chamber and closing the bolt on it, which is the classic scenario for a slam fire. I never encountered the problem, nor did anyone else around me. Now, I would keep my bolt face clean, and try a couple of primed and otherwise empty cases to see how much of a dent your firing pin makes on closing (they do tend to ride forward). There may be cause for concern, and I think CMP cautions on such things, but there's my experience, based on thousands of caps popped in an M1.