I shoot American Eagle with my M1D and have no problems with it. Its 150 gr FMJ boat-tail. For what I'm doing (target shooting under 100 meters), it works fine. Up here the price is quite reasonable too (about $.90 a round). If you're concerned about it, most gun stores stock many different types of 30.06 ammo. You can always buy one of the more advanced (and more expensive) types if you're concerned about damaging the rifle or exactly duplicating the original M2 Ball characteristics.
You could get an adjustable gas plug which will make shooting commercial ammo an option. DCM Adjustable Gas Plug Wrench M1 Garand Steel Parkerized