The M16A2 Buttstock is about 5/eight" of the inch for a longer time then the earlier designs. Due to the amplified duration it used a longer buttstock screw as well as a spacer. The swivel is mounted closer for the buttplate. This buttstock is at present utilized over the M16A4: https://johnathanciklk.robhasawiki.com/10956320/colt_python_6_for_sale_for_dummies