Add this Barrel Assembly to your Multi-Caliber system collection to be able to shoot 9MM. This highly accurate 16” M4 profile barrel is rifled 1 turn in 7”. Machined from 4150M Chrome Moly Vanadium 11595E steel with a Melonite QPQ finish. Assembly includes A2 Birdcage type flash hider. Completely assembled and ready for 9MM Caliber use in the Multi-Caliber system. Requires use of MCS 9MM Blow-back Bolt (P/N 8448501-9MM); MCS 9MM Magazine Well (P/N MCS-MAGWELLASSY-9MM); and the 9MM Buffer (P/N 1005-914-4578-9MM) all available on this website. Made in the USA.