Brownells AR-15/M16 Upper Receiver Action Block Gunsmithing Tool

The Brownells AR-15/M16 Upper Receiver Action Block is a professional gunsmithing tool designed for secure work holding during upper receiver maintenance and assembly. This precision-machined block fits into the barrel extension area of AR-15 and M16 upper receivers, providing a solid foundation for various gunsmithing operations. The tool allows gunsmiths and enthusiasts to safely hold the upper receiver in a vise while installing or removing barrel nuts, handguards, and other components. Essential for proper torque application during barrel nut installation and handguard mounting procedures. The block's design prevents damage to the receiver's finish and ensures proper alignment during assembly operations. Compatible with all mil-spec AR-15 and M16 upper receivers.