Assault Weapon Ban Enhancement Act of 1999

Assault Weapon Ban Enhancement Act of 1999 - Amends the Federal criminal code to direct the Secretary of the Treasury to prohibit the importation into the United States of any semiautomatic assault weapon (including the frame or receiver of any such weapon) that has been modified and determined not suitable for or readily adaptable to sporting purposes, or that includes certain characteristics such as: (1) having a thumb hole stock that functions as a pistol grip; (2) being able to accept a detachable large capacity ammunition magazine; (3) having a fixed magazine which can be readily modified to accept a large capacity ammunition magazine; and (4) using .22 caliber ammunition.