I expect that to shoot out a .30-30 to the point that it no longer had hunting level accuracy would take more than 10,000 rounds. Could happen.
Bore could be damaged by neglect or abuse.
As far as rebarreling goes, strip the front end, turn off the old barrel and turn on the replacement. It will need to be the exact same variation, of course, for the bands, etc. to fit.
M94s are remarkable for the way barrels will interchange, indexing correctly without machining. Of course, headspace will have to be checked, but unless the receiver is worn to the point that the lock has set back, it should be OK.
M94 barrels aren't hard to swap with minimal tools. It is also possible to wreck the receiver.
Place a WTB ad for a take-off barrel. Should be able to find one. There have been millions of .30-30 M94s made.