The .243 is fine for deer, I used to use a 6mm Rem, almost identical ballistics. But honestly if I was to recommend an all around deer/varmint cartridge with occasional bigger game it would be one from the 6.5 family, Swede, Crede etc. As far as recoil, not an huge difference, if you can shoot a .243 comfortably you can shoot a 6.5. After using a 6.5 Swede for deer I would never go back to my 6mm, the 6.5 rounds punch way above their weight class IMO.