Armalite's barrels are custom-made for extreme accuracy and long life. This complete (T) barrel assembly includes a MIL-STD rail gas block, barrel nut, gas tube and handguard cap.
.875 at the journal (Under the gas block)
Caliber: 7.62X51 mm / .308
Barrel: 20" AISI 416R Stainless Steel, Heavy, M-4 Feed Ramps
Rifling Twist: 1:10" RH
Muzzle Device: None
Front Sight Base: Gas block with MIL-STD 1913 rail