Just use 80 grain mono-metal bullets. You should be able to reach something close to 3400 fps and they're amazingly effective. I'd pass on the rechambering, etc., myself. Unless you bump up to 6mm-06 or .240 Wby, I don't think it worth the effort if your primary goal is performance.
Thanks for the replies. Been wanting a Walnut/stainless featherweight for awhile and they're getting hard to find. This will be for my grandson to shoot, he'll be 12 when he gets back from Japan ( his dad'd in the Marines ). He can have it if he gets proficient with it and his dad lets him lol. I'll probably see if Chad would like to play with it and work up a load. Should be here in a week or two.