Quilly, if you use standard ballistics .30/'06 ammo in 165 grain bullet weight or lighter, you will have no problems at all with an M1! It is 180 grain or heavier bullets loaded to max. pressures with H4831 or slower powders that cause M1 problems (bent operating rods). Avoid Hornady Light Magnum and Fed Hi-Energy loads as well, and you should have no problems. The G.I. M2 Ball ammo was loaded with a 150-grain spitzer flatbase and the armor-piercing round with a 165-grain AP bullet. Both loads used however much powder of IMR 4895 or a burning-rate equivalency ball powder to reach a muzzle velocity of +- 2800 FPS @ +-50,000 PSI.