While rebarreling pre-WW2 Mannlicher-Schoenauers, Mod.03, 05, 08, 10, 24, 25 models is no real problem for any gunsmith, it is near impossible with a post-war rifle made from 1950 on. The pre-war ones have a flat-ended barrel that screws against a collar inside the receiver ring, similar to the post-war FN made 98 Mauser actions. This collar, slotted on both sides for passage of extractor and ejector, has inclined rear surfaces that push the locking lugs back on opening, thus achieving primary extraction. Unlike the Mauser action, the M-S has no such incline at the rear of the receiver bridge for the bolthandle root to work against. The rear face of these M-S barrels has cuts for both the extractor and ejector, but these amount to a simple groove across, easy to cut after the barrel is indexed to the action. I have done this cutting with a file once.
After the war Steyr introduced a less obvious variant to the Mannlicher-Schoenauer actions, probably to ease machining at the factory: On the post-1950 actions, Mod.1950, GK, Mc, MCA and NO, the collar inside the receiver ring was omitted. Instead, there are top and bottom projections machined on the barrel itself, their inclined rear surfaces serving the primary extraction of the former collar. This newer arrangement makes it nearly impossible to rebarrel a post WW2 M-S action without having special jigs and gages. The easiest way known to me is: Screw the old barrel out, cut it off in front of the shank/reinforce, bore out the shank, sleeve it with the new barrel. When reassembling, be damm careful to index the shank to the receiver the same way as it was originally.