Bowfinn
Lil-Rokslider
If it’s a roughtec barrel you can have it threaded 5/8-24. I have a roughtec barrel that I had cut and threaded to 5/8-24 at 18 inches.You won't be happy with the results imo, better off buying a take off barrel or just order one. Better yet just sell the roughtec and but a standard ss tikka then your $500 ahead and it's the rifle you want.