Yes, but I'd rather have a low-mont, as close to the bore as possible. The flip-up auxiliary sights will serve should breakage occur, or I've noticed a lot of guys with the M16A3 mounting their backup rear sight/carry handle assembly on the foregrip KAS rail under the foreend, where a flashlight is sometimes also fitted.
Check out the scope on this guy's M4/M16A2....
-archy-/-