For general plains game hunting, anything from .308 on up to .375 is difficult to beat. I've used the 300 Winchester and 300 Weatherby and 180 grain Swift A Frames, and also Barnes X bullets with no complaints. The last couple of years I've used my .375 with either Swift A Frames or Barnes XLCs. With the 300s, and 375, I've taken everything from Steenbok up to, and including animal the size of Eland. IMO, a premium, heavy for caliber bullet is more important than the caliber itself.