 The recoil springs are housed within the receiver, differing from the AR-15 which houses its more elaborate buffer mechanism in the buttstock.The AR-18's compact design enables the use of a side-folding stock with a hinging mechanism (which proved to be less than adequately rigid).The sights are of similar design and sight picture to those of the AR-15 - a 2-position flip aperture rear sight and post foresight - but the rear sight is made of stampings.