Airforce Airforce Condor New Barrel Blank Setting Up Bushing Spacing?

[RM.510bigbore]

Okay so this is my first time making a airgun barrel with bushings. I have my Chaszel blank in .222 diameter machined to same dimensions as factory barrel everything fits okay. I sleeved the blank to 12 mm using carbon fiber sleeve. I brought new Amazon Chinese barrel bushings in 12 mm....Problem is there too tight......I have my factory Airforce barrel with factory bushings that fit perfectly.... I'm scared to remove the factory barrel bushings from old barrel and be able to get space ing right....I'm sure there is a jig or a simple way of doing it I'm completely missing... I'm asking before I act... I can machine or polish the Chinese bushings on lathe to fit..My question is getting holes on frame to line up???Thank you