The customer service man at Ed Brown inspected the barrel and determined the hood had been ground down so far that the barrel couldn't move forward enough , when in battery, to expose enough threads for my AAC Ti-Rant 45M to fully screw down and attach. The Storm Lake threaded barrel I bought, dropped in, fit like a champ, Can screwed down all the way, cleared the end of the slide nicely. Worked like a charm. Now I know.
