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:

• Excellent machinability for gun drilling and reaming, plus exceptional polishability for uniform lapping—a must for bore accuracy.
• A homogeneous microstructure which responds to heat treatment providing a uniform hardness along the length of the bar, necessary for accurate rifling to precise groove dimensions.
• An optimum combination of high tensile strength along with adequate toughness to withstand typical chamber pressures encountered during firing.
• 416R arrives at the factory in long lengths and is then cut to finished barrel length. The barrels are then drilled, contoured and reamed to the bore diameter of the cartridge for which they are to be chambered. The barrels are then rifled, lapped and individually inspected with a bore scope.

NOTE: GAS BLOCK, GAS TUBE and BOLT NOT INCLUDED (300BLK exception)