In RSA, My .338 Win Mag made one shot kills on all plains game, including Eland. Shot factory Winchester 230 grain ammo and the performance was very good - accurate and deadly.
Nothing larger needed for plains game. Proud of my 150 yard shot that dropped a trotting Gemsbok - shot through both shoulders. I have take a cape buff with my .405 and I would feel confident taking Cape Buff with .338 Win Mag.

My PH was impressed with the cartridge and with my Ruger 77 rifle.