5.56X45 mm / .223
20” triple lapped, AISI 416R stainless steel, M-4 feed ramps
Front Sight Base
Gas block with MIL-STD 1913 rail
Armalite’s barrels are custom-made for extreme accuracy and long life. This complete (T) barrel assembly includes a MIL-STD 1913 rail gas block, barrel nut, gas tube and handguard cap.