I use USGI cleaning kits, exclusively. I rub a small amount of carbon residue on the threads of the gas screw, and make sure it's tight, but not "gorilla" tight. If the screw works loose, your rifle will make groups that look like a shotgun pattern, you'll know right away something's wrong. I always use milsurp ammo, although Hornady and Federal make Garandicon-specific ammo now. My favorite is Greek HXP M2 ball, followed by USGI. Here's another excellent site for Garand shooters/collectors: CMP Forums