My boss has a Colt AR15 HBAR with an A2 upper. It's a commercial model with the big-hole upper. He wants to mount a scope on it, a Zeiss with short eye-relief. Ideally, a flat top and Larue mounts would be our first choice, however, given the big-hole upper, I am at a loss as to how to make this happen. I would appreciate your experience and recommendations in this matter in this matter.
For info, I'm a ceritified AR15 LE armorer and have all of the vise blocks, barrel nut wrench and torque wrench to perform barrel swaps, etc.