41 Caliber Crimp on Gas Checks for Lyman Bullet Molds .397" Shank Bag of 1000

41 Caliber Crimp on Gas Checks for Lyman bullet molds and others measuring .397" on the shank and is used on all 41 caliber Lyman bullet molds and a few custom mold, bag of 1000. If you cast your own bullets, these crimp-on gas checks will enhance their performance. During sizing, gas check crimps to the base of cast lead bullets to seal gasses and protect the base from deformation.