I just got back from Africa a week ago where my best friend and I both shot Buffalo along with some other animals.
I will say this. You need to shoot what you are the most comfortable shooting with the highest degree of accuracy.
I personally took my 375 H&H in Win model 70. I used my hand loads which I worked up using Barnes 300 gr TSX bullets and RL15 powder.
My one shot through the front of his chest as he was staring me down took out the top of his heart.
View attachment 553500
I took this photo at the range after we arrived in camp and verified rifle zeros. This orange sticker is 1 inch diameter and these three shots were from sticks at 100 yards.
I will take my 375 any day of the week over a bigger caliber I flinch to shoot but feel I need to use just because it is “bigger”.
Use we what you can shoot accurately and with confidence.