I agree the .260 is light
But if a 140/2750/.56BC was used it would have still over 2050fps and 1300fp of energy at 500 yards. Personally I wouldn't use the .260 full stop, but the figures are about the minimum limit what many hunters do use. Is it enough? I don't know for sure as I've never tried it. I know many who would argue, that's plenty.