The Speer bullets work well on plainsgame, deer and perhaps up to elk size animals. The biggest thing I have shot with them is a cow elk and it worked just fine..I have shot a lot of big stuff with the Woodleigh 235 gr. PP and I wouldn't hesitate to use it on elk, moose or eland for that matter, its a killer and it holds together much better than the Speer.
But for the most part I would suggest that one use the 250 gr. Sierras, they are cheap and not soft like most Sierras and work well on most all big game. I have had great luck with the 250 and 300 gr. Sierras on deer and elk.