I have seen my little bro shoot four or five deer and as many elk with his 338-378 wich I think is very close to the 338 lupua. It works very good, and if you get a shot at an elk past 400 yds and can place the bullet it still packs tons of energy way out there. My bro shoots factory 250 grain nosler partitions for everything and so far so good. The weatherby rifle with sawro scope isn't as heavy as the sako but with the muzzle brake its a pussy cat to shoot, take the brake off and well you get real personal with an expensive scope. The sako should be a good elk rifle but might start to suck when the hills get steep.
just for kicks we vaproized a few jack rabbits with it in eastern Oregon, has pretty much the same effect as a 22-250 with 40grain HP's only it costs over five bucks a shot, it was worth the money.