I've a 760 switch barrel rifle with barrels in 376 Steyr(requires a separate bolt with opened bolt face), 9.3x62, 338x06, 30-06,'270', and 416x06 imp. All larger than 30 were rebored from early barrels with dovetail rear sights. Be careful with the barrels with screwed on sights as the holes are pretty deep. Cliff LaBounty did some of the rebores and Jim Dubell did the 9.3. All are top notch. Results in a unique rifle with many attributes different from a bolt gun. Barrels can be swapped in a couple of minutes with only a 6"piece of drill rod to use as a wrench for loosening/tightening the under barrel rod/nut.
Otto