Helix 6 Precision Helix 6 Precision Carbon Fiber 20in 22 ARC Rifle+1 Rifle Barrel 243cal 0.75GB1-7 Twist 1/2-28 threaded muzzle 20 in AR-22ARC7-20R1. Simply install headspace and head to the range. Our AR barrels use hand lead lapped button rifled 416R...