14.5" Chrome Lined Barrel

Length: 14.5", 1:7" Twist Chamber: 5.56 mm Profile: M4 Profile Material and Finish: 4150 CrMoV Chrome Lined, Phosphate Finish Muzzle Thread: 1/2"-28 TPI Gas Port Location: Carbine Gas Block Size: .750"

16.1" 5.56 MM Barrel Sub-Assm 4140 Chrome Moly

Barrel Sub-Assm, 16.1" MT 4140CM SBN, 5.56mm Length: 16.1", 1:7" Twist Chamber: 5.56 x 45 NATO Chamber Profile: Medium Taper Profile Material and Finish: 4140 CrMo, Salt Bath Nitride Finish Inside & Out Muzzle Thread: 1/2"-28 TPI Carbine Length...