Armalite's barrels are custom-made for extreme accuracy and long life.
This complete barrel assembly includes a MIL-STD 1913 rail gas block, barrel nut, slip ring, slip ring spring, slip ring retaining ring, gas tube and handguard cap.
.750 at the journal (under the gas block)
Model: AR-10 A4 post-ban carbine barrel assembly
Caliber: 7.62X51 mm / .308
Barrel: 16" chrome lined, 4140 steel, M-4 feed ramps
Rifling Twist: 1:11.25" RH
Muzzle Device: Permanentley afixed muzzle brake
Front Sight Base: Gas block with MIL-STD 1913 rail
Finish: Manganese phosphated steel