if mule deer is the quarry, i take my 270 which will also handle bull elk nicely. if after elk i use a 338. africa i've used 308, 338, 9.3X64, 375HH, and 416 rem. all one weapon safaris. limited to one rifle for north america i would probably choose a 30/06. for africa the 416 because my experience is the 9.3 and 375 are a bit light for the big stuff. that said, its a lot easier to find 375 ammo in africa than maybe anything else with the exception of 7.62X39.