Proof Research's steel barrels are produced in-house from double-stress relieved 416R stainless steel. This pre-hardened chromium steel is ideally suited for match grade rifle barrels. Each barrel is drilled, contoured and reamed to bore diameter. It is then cut rifled, lapped, and inspected via borescope. This ensures an extremely consistent and accurate finished product.The aerospace-grade carbon fiber used has a specific strength up to 30 times that of stainless steel and a specific stiffness up to 7 times greater than steel. But strength and stiffness are only part of the equation. Heat conductivity and thermal expansion are also of paramount importance when developing a match-grade carbon fiber barrel. Proof's helical wrapping pattern favors the longitudinal thermal diffusivity of the carbon fibers (along the length of the barrel) allowing them to more efficiently dissipate heat emanating from the barrel rather than insulating it.Because Proof's rifle barrels are engineered for...