The M16A2 buttstock is about 5/eight" of the inch lengthier then the earlier models. Because of the enhanced size it utilized an extended buttstock screw in addition to a spacer. The swivel is mounted nearer for the buttplate. This buttstock is at this time utilized on the M16A4: The "C" https://gold-cup-trophy-colt-4568011.birderswiki.com/1037771/not_known_facts_about_colt_combat_unit_rail_gun_45