PROOF Research pre-fit carbon fiber & steel barrels for the Defiance Ruckus are to be installed in a simple operation requiring few specialized tools. Their pre-fit barrels are chambered and threaded for a simple install that require only a few specialized tools. Simply torque your barrel on, double check headspace with proper gauges and head to the range! Unprecedented accuracy and performance - it does not get much better than our Defiance Ruckus carbon fiber & steel pre-fit barrels. Long-Lastin Stainless Steel Barrels Extreme pressure resistance Double Stress Relieved 416R Stainless Steel PROOF drop-in barrels are designed to fit Mfg: Proof Research