“Semi-automatic AR-15s for sale to civilians are internally different from the full automatic M-16, although nearly identical in external appearance. The hammer and trigger mechanisms are of a different design. The bolt carrier and internal lower receiver of semi-automatic versions are milled differently, so that the firing mechanisms are not interchangeable. This was done to satisfy United States Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) requirements that civilian weapons may not be easily convertible to full-automatic.”
“There are no federal restrictions on the ownership of AR-15 rifles in the United States. During the period 1994–2004 variants with certain features such as collapsible stocks, flash suppressors, and bayonet lugs were prohibited for sales to civilians by the Violent Crime Control and Law Enforcement Act of 1994, with the included Assault Weapons Ban.”
“Included in this was a restriction on the pistol grip that protrudes beneath the stock, which was considered an accessory feature under the ban and was subject to restrictions. Some rifles were manufactured with a grip not described under the Ban installed in its place. Those AR-15s manufactured with those features, as well as the accompanying full capacity magazines, were stamped “Restricted Military/Government/Law Enforcement/Export Only”. The restrictions only applied to guns manufactured after the ban took effect. It was legal to own, sell, or buy any gun built before 1994. Hundreds of thousands of pre-ban ARs were sold during the ban as well as new guns redesigned to be legal.”
Thank you. Sounds to me like the assault weapon ban had more to do with cosmetics rather than functionality.