Brownells Aircraft Counterbore 9/16" Piloted

The Brownells Aircraft Counterbore is a precision gunsmithing tool designed to cut clean, flat-bottomed counterbores with a piloted guide for accurate, centered results. The 9/16" size makes it well suited for screw head seating and recessing operations common in firearm assembly and repair. The pilot ensures the counterbore remains concentric with the existing hole, delivering consistent, professional-quality results on metal work.