The M16A2 buttstock is about five/eight" of an inch lengthier then the sooner designs. As a result of elevated length it made use of an extended buttstock screw plus a spacer. The swivel is mounted nearer towards the buttplate. This buttstock is at present made use of on the M16A4: https://victorydirectory.com/listings509949/helping-the-others-realize-the-advantages-of-colt-combat-elite-commander-45-acp