The easiest answer is only shoot cmp ammo in a cmp gun.
However, you can find special ammo from hornady that is folmulated just for the garand gas system and you can reload with "Garand" specific recipes.
These recipes must duplicate bullet rate, velocity and most importantly burn rate. If not one shell can bend an operating rod.
Best thing is just shoot cmp surplus ammo until they run out.
Sorry that was meant to say "bullet weight" not "bullet rate".
Last edited by bcarver; December 25, 2008 at 03:05 AM.