harold - sometimes those things can be a pain to get off. Some even go on with reverse threads, that is, the barrel twist is to the right or left and the threads go in the opposite direction so the things don't shoot loose and fall off. Back when Layne Simpson wrote his book on building a custom 45, there were a number of compensators you could install yourself right to the slide in place of the bushing and the barrel rode through it when the slide recoiled. Some, however, were screwed on and some even had a small retaining screw to hold it on. I think your may be onna those that may need 3 hands to remove, or a good gunsmith who knows what he's doing. Good luck with that beast, and please let us know how it finally got removed. Thanks. Mikey.