No doubt, if that's what you want to use.
In my experience, not just on buffalo but a wide variety of game, various calibers (as in bullet diameter, not cartridge) work very well, as long the the bullets are put in the right place and penetrate and expand sufficiently.
Long ago lost count of the PH's (and their teenage kids) who've killed buffalo very well with cartridges far under 9.3/.375 diameter, using bullets weighing 175-200 grains. The most PH I've hunted with the most, also among the most experienced, grew up in what was then Rhodesia. One of his early jobs was shooting buffalo on a big cattle ranch, both for meat for the ranch workers and to clear the country for commercial beef cattle. He killed over 500 with a .30-06 and 180-grain Nosler Partitions, and not by head-shooting at night, but on day-time drives, with the ranch workers pushing herds toward him. This includes everything from calves to big bulls, and he never had a problem. (He preferred the .30-06 to larger cartridges, due to being able to get more shots off in a hurry, thanks to lighter recoil.)
Later on, after he'd been PHing for decades, he often used his .375 H&H as backup on buffalo hunts--though he sometimes chose his .458 Lott (which he preferred for elephant guiding) in thicker stuff. He said with the .375 he was often "way under-gunned" compared to his clients--but on a number of occasions had to finish off their buffalo. I asked him about his preferred bullets, and he said he'd used at least a half-dozen different "softs." This was due to ammo being so expensive and, sometimes, hard to find in various African countries. As a result he used whatever left-over .375 ammo his clients left behind, since "these days all the bullets are so good." The ammo shot close enough to the same POI at typical back-up ranges to work fine.
