Used 26 Inch Proof Carbon Fiber Sendero 300 Win Mag Cut for Big Horn Long Action (Origin and TL3 have had on both) Threaded 5/8x24..........This is not a prefit from proof this was cut and chambered by a Gunsmith not known to me as I picked this barrel up on here about a year ago.......Original Owner said under 200rds fired and looking at it with scope I would say thats right....I have put 40 rounds through it with 205 Bergers and gun was easy 1/2-3.4 moa gun with the little load work up i did....Will work on TL3 Or origin as I have had it on both..........500 Shipped .......