Geissele AR-15/M4 Reaction Rod Upper Assembly Tool

Geissele AR-15/M4 Reaction Rod Upper Assembly ToolThe AR-15/M4 Reaction Rod makes removing and installing barrels, flash hiders, gas blocks, and handguards much easier. The Reaction Rod is designed to be gripped in a bench vise, with the rod either horizontal or vertical. You then slide the upper receiver onto the rod, and the rod's integral splines enter the barrel extension and prevent it from turning. This allows all the torque from barrel nut wrenches to go directly into the barrel extension. In contrast, receiver vise blocks transmit turning force into the aluminum receiver, much of which passes through the small, easily distorted receiver index pin. With the Geissele Reaction Rod, marring of an upper receiver's finish by gripping and twisting inside vise blocks is eliminated, and so is the need to remove sights and mounts from the receiver's M1913 rail.