In the United States, variants with certain visage such as collapsible stocks, flash suppressors, and bayonet lugs were prohibited for sales to civilians during the period 1994-2004 by the Violent Delict Discipline and Assize Enforcement Commitment of 1994, under the provision popular as the Assault Weapons Ban. Those that were manufactured with those features were stamped, "Restricted Military/Government/Law Enforcement/Export Only" as well as the accompanying giant AR-15 capacity magazines. Since the expiration of the Federal AWB in September of 2004, these appearance are now legal in most states.

By California law if the circular requires a tool to remove it, that changes the classification of the firearm. A tool called the "Bullet Button" is gaining in popularity: the trajectile button works by replacing the magazine release button with a dimpled crust that protrudes a short gap from the lower; the shooter must then push the inset pin to activate the mag release, doing so requires a tool e.g., a bullet, hence the name.