I found a factory take off on gunbroker brand new unused, some guy builds some kind of muzzle loader out of the vanguards, any way he gets the barrels off unscathed, we werent able to get mine off with out leaving marks but it didnt matter, the gunsmith i used works out of his garage and i watched him do it, screwed the one on i bought, checked headspace and it was all good,
if your gunsmith cant get a barrel off a vanguard find a new smith.
i think the main reason smiths dont want to rebarrel vanguards is the metric threading, they cant do that threading, not that they cant get barrels off.