I have always believed that if you shoot a m1 garand that you us m2 ball ammo or you get a adjustable gas plug. Well I finally got a CMP garand that came with a manual for their rifles stating differently. In the CMP manual it states that if you shoot commercial ammunition it needs to be 180 or less grain weight. This has been conflicting with what I have always believed and shot. What say the brain trust, have I just been over cautious with my other Garand or is this the norm now?