Own a piece of firearm history from the makers of the world’s most battle-proven firearms. The FN 15® Military Collector Series M4 upper receiver assembly is an authentic reproduction of the original made to FN’s and the U.S. military’s exacting specifications. A 14.7-in. chrome-lined barrel is button-broached with a 1:7 twist rate the welded compensator brings the barrel length to 16-in. Cut with a 5.56x45mm NATO chamber to mate with the Carpenter 158 steel bolt each MIL-SPEC bolt carrier is high-pressure and magnetic particle tested for enduring reliability.
 

• CALIBER: 5.56x45mm
• WEIGHT: 4.98 Lbs.
• BARREL LENGTH: 16"
• OPERATION: DIRECT IMPINGEMENT CARBINE-LENGTH GAS SYSTEM
• TWIST RATE: 1:7 RH
• SIGHTS: A2-style front adjustable rear sight