On my 75b with chrome 10x bushing i had the same problem, after the first range trip and 250 rounds it is still a tight fit, but when the gun is field striped and u have the slide off the frame i press on the barrel from the ejection port with your thumb with some force and then yank the barrel down from the slide. Then to reinstall give it a firm push with your palm. This is all when the gun is unloaded of course. It gets the job done just have to man handle it a bit more than before.