This Surgeon 1086 long, repeater action has .473" bolt face diameter to fit a .308 Winchester with a Remington style extractor. It has a .25" recoil lug, tactical bolt knob, 20 MOA 1913 picatinny rail, side mounted bolt stop to prevent accidentally releasing, an anti-jam rail to prevent a round from lodging in the raceway, and an anti-bind rail. Action Material:4140 Chrome Moly 38-40Rc in whiteLength:8.975"Thread:1-16 16UN 3BThread Length:.954"Action Profile: Round BottomWeight:2lbs 5ozLoading Port Length:3.8"Ejection Port Length:3.35"Bolt Material:4140 Chrome Moly 38-40Rc and Ion Nitrided Surgeon LA 1086 Repeater Action 1086-R-308