In an open letter sent to Federal Firearms Licensees in April 2006, the ATF stated their interpretation of the law: that installing a vertical forward grip on a handgun is the same as manufacturing an Any Other Weapon (AOW) category firearm and subject to registration and taxation, with significant penalties for manufacturing or possessing such an unregistered weapon.U.S. Department of Justice, Open letter to Federal Firearm Licensees concerning Adding a Vertical Fore Grip to a Handgun. Published April 10, 2006.
