375 is a noticeable bump up from a 35 Remington. I can't find my load data but from memory, 40grains ish of AA1680 gets a 220gr bullet going 2400 fps and the 200grainers close to 2500 fps. I don't think I ever got the 200gr much past 2400 fps but the 220s were definitely at or just shy of there. Recoil is...noticeable.
Use Starline short 38-55 brass and you get a lot more case capacity and it will still run at least in Marlins. In a Winchester BB I think I had some OAL issues with 38-55 brass. Sierra makes the 200gr and I ran the 220gr from Vollmer. Knocks the snot out of deer.
