Robie:
I have used a .416 Taylor for well over a decade, and can't speak highly enough of the cartridge as a heavy-medium bolt-gun chambering. The shoulder-shot absolutely stuns buff! Simply marvellous!

With the cheaper 400gr Taipans for pigs, Woodleigh Weldcores for buff, and either Woodleigh or Hornady steel-jacketed solids for ponderous game, there's nothing it can't handle. ...and plenty flat enough for plains game I imagine, especially with spitzers or the Woodleigh PP bullet. I have never loaded down from the 400-grain bullet myself, but those who have report good results with 350-grainers or Barnes X.

Its relatively easy to get 2400 fps with ADI powders if you really want to, and matching original Rigby ballistics is a snack, but I don't bother pushing that hard. The 410gr Woodleigh RNSN at 2280 fps is my working load, pass-throughs are common even when a shoulder is smashed, and cases last forever.

My rifle is a back-shed custom job, Walther barrel on a 1942 CZ Mauser'98, modified military stock, 10 pounds even. Express sights, no scope. I mostly shoot doubles these days, so its often a loaner: two of my mates collected their first buffs with this rifle last dry.