Description These AR-10 /LR308 barrels are machined from 1:12 twist 4150 barrel blanks, and externally blackened with 2400 Series Bake-On KG GunKote. .750″ diameter gas block journal, with a 5/8-24 threaded muzzle. .740″ diameter in front of the gas block, .800″ diameter behind the gas block. We do not recommend using this barrel without an adjustable gas block. With .375 bullet weights ranging from 137 grains to 400 grains, running both super and subsonic with powder charges ranging from 14 to 50 grains, there is no single gas port size that can function the gun properly, especially considering the use with and without a suppressor installed. With that in mind, we simply drill the gas port to .073″ to handle all supersonic full power applications with an adjustable gas block installed. Optional .110″ sub-sonic gas port is also available. 12″ barrels have a carbine length gas system, 16″ and 20″ have a mid-length gas system. These barrels will not work with the Ruger SFAR.
