I have a factory 20” varmint contour .308 barrel that I had threaded and the smith threaded it crooked. Will need to be cut off and re-threaded or crowned at approximately 18.5” give or take. Came off of a SPS Tactical. 12 twist, Maybe 250 rounds down it and would shoot .5 to .8 groups all day before the crappy thread job. Couple marks on it from removing it because it was a b***h to get off.
BP