Volquartsen's Lightweight Carbon Fiber Barrels have evolved. Inspired by their success with the Lightweight Carbon Fiber Barrels for the 10/22, they've applied these improvements to the new complete Volquartsen Lightweight Upper for the Ruger MK IV. Each barrel is made from stainless steel and features a laser-hardened breech face for maximum durability, even at extreme round counts exceeding 100,000. Volquartsen's unique design utilizes a woven carbon fiber sleeve for rigidity while still providing an air space between the sleeve and barrel for heat dissipation. This barrel is then threaded into a Ruger MK IV upper receiver. This upper is paired with an Upgraded Ruger MK IV frame and our Competition Bolt.