Chambered in 5.56×45 mm (.223 Rem.), the FN FS2000® Tactical is a civilian legal, semi-auto only variant of the proven FN F2000® selective-fire bullpup carbine that offers an integrated MIL-STD-1913 top mounting rail and emergency backup folding sights. The FN FS2000® carbine is gas-operated and uses a rotating bolt lockup for reliability and greater accuracy. Its 17.44-inch cold hammer-forged MIL-SPEC barrel is fitted with a muzzle brake. Fired cases are ejected through a forward port away from the operator. The thumbhole design polymer stock is ambidextrous.