Jacket wall thickness is only part of the equation in bullet strength. Strength and hardness of material makes or breaks the bullet, so to speak. In looking at the 300gr. RN, the jacket appears it would be super tough, just as the Spire point seems to produce at even higher speeds, yet it is a much 'softer' bullet on game.

I'd try those Taipans or whatever they're called, in Australia - suppose to be a very soft bullet. I'm not suggesting them for buffalo, but maybe deer and pigs? Too, they're cheaper for plinking, I'd imagine. A bonded Woodleigh might just be the ticket for the really heavy game at the 9.5 x 57mm's lower speeds, perhaps it would be a cross between a soft and solid, depending on what it hit. At very low speeds in the 2,100fps range, that also seems to be the 'action' of the 300gr. Hornady RN.