... Just about any carry handle that's not deformed and designed for an AR-15 will work. It'll screw on, and attach just fine. You can sight it in. Some will work BETTER than others of course...
That's generally true, JimDandy, but you're almost guaranteed to have a wobbly sight post if zeroed at 100 yards and the front FSB is not F-marked while the rear is milspec height. Fortunately a $10 Bushmaster 0.04" taller post will solve the problem.