You can also file a “slightly” larger area than already exists at the base of the slide where the cartridge seats in the slide, below where the firing pin hole is, on tight fitting barrel after the 10x bushing is installed that is where the barrel gets hung up, have had to do this on occassion for the really tight barrels that needed more than lightly tapped in, otherwise they will not come back out in a proper manner until several hundred rounds are cycled to loosen up the bushings tolerance. Doesn’t take much filing just take some time and test fit often…..a light tap to get the barrel in is fine, anymore than that and a little filing will do the trick. This can be done with the barrel installed too, just slide the barrel forward when filing.