Anything that is PMC Bronze-equivalent, and up. 147~150 grain, loaded by a major ammo manufacturer. PMC, Winchester, Remington, whatever. As long as it's mainstream ammo, it'll function your rifle. Lighter loads, with 147-grain being the minimum, run at a higher muzzle velocity over heavier loads. Anything 180-grain or over might have issues fitting into your magazines. 175-grain is the common max projectile weight that you can load to magazine length, though there are a few heavier projectiles that will still be okay loaded to 2.800" - not many, though. As a rule, stay away from 180s and up for magazine loading, unless you do homework on the projectile, and it's loading.