Fans of the new Defiance Machine Ruckus actions will be an even bigger fan of the PROOF Research prefit carbon fiber designed for the Defiance Ruckus action. PROOF's Ruckus prefit barrels will arrive threaded and chambered. This is a shouldered barrel that requires few specialized tools for install. They're offered with a variety of caliber, lengths, and twist rates in carbon fiber.
* These PROOF Research/Defiance Ruckus prefit barrels are pre-headspaced. However, it is always recommend to double check headspacing with proper gauges before firing a rifle.