When I was in Africa this year, I brought a 458 Lott for buffalo with 500 gr TBBC. Brought a 300 Wby with 180 gr ttsx for everything else. My PH saw me shoot both and said, "you don't flinch with the 458, and you're shooting less than 1" groups at 100 yds. So leave the 300 Wby at camp." I didn't necessarily think it was a great idea going into it, but I listened to him. It was my first trip to Africa, and figured he knew best.
I proceeded to shoot everything I got with the 458 lott. Sable, buffalo, zebra, kudu, wildebeest, and impala. Was it more than I should have used? Especially shooting 500 gr bullets. Most certainly. Did we waste any time tracking anything? Nope. Everything except the wildebeest, ran 2 inches.
Most of the shots were inside 150 yds. Wildebeest was about 275 yds if my recollection is correct, which was a stretch with probably 13" drop. I shot low on that one. But got lucky and hit him a 2nd time running away at 350ish yds.
If I was going again for PG, using a 458 for everything wouldn't be my plan. I'd probably bring the Weatherby again, because I still think that was more appropriate. Maybe a 338 Win Mag. But if the 458 was my plan, I'd get some lighter tsx.