Actually, powders with a slow burn rate are damaging to the op rod. The slower powders (along with heavier bullets) generate increased pressure at the end of the barrel where the gas is bled to operate the gas system. Several manufacturers load ammunition specifically meant for the Garand. Generally, you need to look for ammo with bullets weighing 175 grains or less (150 is preferred).
My choice for removing light rust is rubbing lightly with CLP and 0000 steel wool.
Okay. Thanks for helping me out.
Actually, that is not true. It is an old wives' tale repeated often enough by ill-informed gun writers copying each others drivel that it has become believable by many otherwise knowledgeable gun nuts.
Please cite even one reliable source that details experiments containing data on the subject.