Bore guide designed to limit muzzle damage from cleaning rods, for use with the M1 rifle. This guide is designed for a more secure fit than those that can be purchased from commercial vendors, as it indexes off the gas cylinder lock screw.I created this muzzle guide from the ground-up by measuring my late H&R M1 rifle. This guide has a 6.8mm hole for use with a Dewey .30 caliber coated rod.