Just tried to remove a smooth barrel nut. Fresh/sharp 15" pipe wrench, after 2 days of drenching in Kroil. The only thing that turned was the barrel in the barrel vise. After tightening I tried again with my considerable body mass leaning on the wrench. I will continue soaking with Kroil and try again in 2 more days. Any suggestions. I have to be putting around 100 - 150 foot pounds on it.