Fans of the new Defiance Machine Ruckus actions will be an even bigger fan of the PROOF Research prefit stainless steel designed for the Defiance Machine Ruckus action. PROOF's Ruckus prefit barrels will arrive threaded/chambered with 5/8x24 muzzle threads. 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 stainless steel..
* These PROOF Research/Defiance Machine Ruckus prefit barrels are pre-headspaced. However, it is always recommend to double check headspacing with proper gauges before firing a rifle.