When you want a serious mount for your AR-15, then you want the Warne Scope Mounts R.A.M.P. 30mm Scope Mount.  The Rapid Acquisition Multi-Sight Platform, or R.A.M.P, is a cantilever style scope mounting platform that allows proper scope installation on the popular AR-15 rifle.  By design, the AR platform was intended for fixed iron sights and did not offer an acceptable mounting surface for optics.  As the weapon system evolved from the military designate M16A1 to the M16A3 and M4, Picatinny mounting systems became standard equipment.  The new WARNE R.A.M.P modular mounting system positions the front ring forward of the upper receiver by 1 3/4".  This allows the optics to be mounted farther forward enabling the shooter to have proper head orientation whether upright or prone without sacrificing or compromising due to improper positioning.