Whether or not the Encore could be chambered in a particular caliber would depend on the pressure the cartridge generates and on the diameter of the cartridge (larger diameter means less metal around the cartridge). Thompson/Center chambers barrels in such heavy hitters as the 300 Win. Mag., 375 H&H Mag. and 416 Rigby so chamberings in such Weatherby calibers at 257, 300, etc. should not be a problem. You could try Fox Ridge Outfitters and talk to the Custom Shop; they might make a special chambering for you.