Re: switch barrel gun does anybody use one ?
Try Montour County Rifles, he advertises here.
Most good gunsmiths will keep your chamber dimensions on file, so that they can easily chamber another barrel to match the first. But be sure to torque the barrel about 50 ft. lbs., (get the appropriate action wrench) then check it with go/no go guages. The headspace must be on to the last .0015".