Re: chamber/cartridge adapters
John, the Savage M-24 will handle a Hornet, no sweat; it was chambered in .222, as well, a much higher pressure, and larger, round.
I assume the adaptor is to increase versatility of the arm; this being said, no chemicals, beyond bore solvent, and oil, should be involved.
Savage used to market a 'Four Tenner' insert, to allow the use of the smaller gauge shells in a 12, or 20 ga shotgun; while not particularly accurate, they worked ok.
At one time there was a company offering .357 Mag/ .38 Spl inserts for shotguns, as well, sort of a "Poor Boy" Drilling Kit. Also, not particularly accurate, but very functional!
A parting thought; if you handload, the Hornet can be loaded to anything from rimfire to .222 specs, which may eliminate the rimfire adaptor, entirely!
Don't start no s**t and there won't be none, Terry