Be sure that you are using no powder slower burning than IMR 4320. IMR 4895 is THE powder that the ammo was loaded with for the M1 Garand. Keep your bullet weight down to 180 gr of lighter. This is to keep port pressure where it is supposed to be and also not to beat up your op-rod. The reason that many do not load a case more than 4 times is because the M1 beats the snot out of them. The rims get bent in and chewed up quite a bit. It is not that the case will rupture or anything. When the rims get bent in and chewed up you can have extraction issues, IE pulling through the rim or the extractor just slipping off or misses the rim. Standard loads for the M1 Garand is 47 to 48 grs IMR 4895 with 150 to 155 gr bullets or 46 grs IMR 4064 with 165 to 168 gr bullets. I have used all makes of primers and the only one that you should not use for slam fire issues are real is FEDERAL. I personally have had slam fire double and triple fire using FEDERAL primers. They are really sensitive and the free floating firing pin of the M1 Garand can and WILL set them off when a round is chambered in the firing cycle. My match load for my all matching 1954 Springfield M1 is 48 grs IMR 4895, CCI-BR2 primer, LC Match case, 155 gr Nosler custom competition HPBT, OAL 3.334 and I use a Lee Factory Crimp Die on it because it makes it more accurate. Good luck and good shooting.
