Things You'll Need
Instructions
Unscrew and remove the retention nut located on the bolt on the bottom of the rail mount. Position the mount so that the slanted grooves on the mount's sides line up with the angle of the carry handle.
Place the mounting bolt through the hole located on top of the carry handle. The mount should seat naturally into the top slot of the carry handle. The surface of the mount should be parallel with the rifle's barrel.
Place the retention nut back on the mount's bolt and tighten. M-16 rifles almost exclusively utilize Weaver-style scope mounts and rings.
Attach your scope by loosening the mounting screws at the base of your Weaver-style scope rings, widening the mounting bracket, placing the rings on the mount, and tightening the mounting screws.