Use a 165g Bullet, It'll shoot any of them but a Spitzer Boattail will be best. IMR 4895 is actually the powder used in the Garand Ammo and is what the System was designed around (if I recall correctly). Hope this helps.
Go to "master poe's temple" web site and click on m1 load data (from the NRA) and READ the articles there and also from FULTON ARMORY . M1's are fun to shoot, but have a few little quirks you should be aware of.