.30-30 and .303 rotors were the same, as were all receiver internal dimensions for every caliber Savage built up until the .308/.243/.358 were introduced in the 50's. Even though Savage rotors were caliber specific, it's amazing how well they'll feed different cartridges nonetheless. Out of curiosity I fed a couple .38-55's into one of my .303 takedowns with the barrel removed and I got two in easily, the third would've been problematic so I didn't push it. They lifted out of the rotor fine but the cartridge guide was the bugabear- they didn't want to snake straight ahead. If I built a .38-55 (and I have a couple orphan M1899 actions that tempt me to do one of those) I would be comfy having a two shot repeater, plus one up the spout. It's the cartridge guides in those things that are the real determiners.

If I feel ambitious maybe I'll try that trick with a couple of my other takedowns, just for giggles. (.22 High Power, .300, .250-3000 and .3030.)