7x57 is an amazing cartridge. People seriously underestimate its potential. Modern ammunition is seriously underloaded because there are rifles chambered in this cartridge going back over a hundred years now. You will find the ammunition for military small ring actions was loaded around 51,000 CUP where modern ammo MAXES out at 46,000 CUP. With proper milsurp ammunition loaded to military specs (154grn spitzer boat tail at 2,900Ft/s), 7x57 will shoot flatter than most 308 or 30-06. I personally have a Chilean small ring that I hand load 175 grn SMK's for. It will shoot 1/2 MOA all day long and has never failed to kill anything I pointed it at. Milsurp ammo is still readily available in large quantities for a decent price. I have 2,070rnds of reloadable Winchester military full pressure 7x57 for sale right now on the classifieds for .46/rnd (compared to $1/rnd+ for modern). And I have another 15,000rnds of mixed surplus in boxes in my closet. Not to mention my Chilean is considered an Antique so it isn't on paper anywhere. I would seriously consider rechambering or rebarreling in 7x57. It's ballistics are nice, accuracy is awesome, shoots soft, hits like a hammer, and ammo is cheap.
