When PROOF Research joined Lawrence Barrels in 2012 they acquired 15 years of experience in manufacturing precision steel barrels. PROOF manufatures stainless steel barrels in-house with an absolute commitment to extreme accuracy and quality. They start with double stress-relieved 416R stainless steel, a pre-hardened chromium stainless steel ideally suited for use in precision, match-grade rifle barrels. 416R was specifically designed by engineers in collaboration with barrel makers and rifle manufacturers to provide the consistency, high quality and durability the firearms industry demands. 416R is the material of choice because it has the following characteristics: Excellen Mfg: Proof Research