The M16A2 Buttstock is about five/eight" of the inch more time then the sooner styles. Due to improved duration it utilized an extended buttstock screw and also a spacer. The swivel is mounted closer to the buttplate. This buttstock is at present applied over the M16A4: The modification system explained https://colt-m16a1-for-sale89743.tdlwiki.com/1064311/5_easy_facts_about_colt_combat_elite_commander_45_acp_described