I too wonder if the rotary magazine will with with the larger necked cartridge. However, as the .22 Savage High Power was just a necked down 25-35, that one just might work.
From your picture, your rifle looks like a take down model. You might remove the barrel and see if the 25-35 will fit the rotary magazine. I think if you have to go to 30-30, then you might need to chane the rotary portion of the magazine.
My next question is this; is the 25-35 now legal to hunt deer in California? I left that leftist state permanently in 1970, and at that time it was not considered powerful enough for deer because it only had 995 ft. lbs. of energy at 100 yards and 1,000 ft. lbs. was considered legal. WOW, a whole 5 ft. lbs., as id any deer could tell the difference.
I do have an old 99 complete action with the rotor for the .303 Savage. I got it for spare parts when I had a nice 99 in .303 Savage, but since I sold that gun off, it's been sitting in my shed.
If it turns out your rotor won't work, you can have it for what it cost me, $50. The 30-30 will feed just fine with a .303 Savage rotor.
Anyway, the option is still there if you need it. it will have to be sent to an FFl of course to do things legal.
Paul B.