Well, I'm not singularly a proponent of Sierra products but I do think they get sold short sometimes based on unfounded assumptions. I know my eyes were opened when I actually tried some of their big heavies- they aren't the bombs that some of the lighter calibers can be at times, especially when they are driven at impact velocities greater than Sierra recommends. Sierra does make - and has dropped - some very excellent and useful bullets (presumably due to lack of sales in regard to those which have been dropped.) I do like the forthrightness of the company employees: when I queried them about their 300 .458 for use on moose, they were honest and said it would probably be okay under just the right conditions but said a 350 or 400 would probably be even better - weights they don't even make! (How many companies will basically come right out and say, "Yeah, you should use a Hornady or Speer bullet instead of ours?") I have never entertained the idea of using their 300 HP for moose anyway but I thought I'd see what they said in light of the fact that they do show some moose in their books taken with it.
I have had more one shot, on-the-spot-drop kills on big animals like moose with "regular" bullets (like the Sierras) than with the premiums - and I haven't had a Sierra in the bigger calibers and weights go off like the proverbial bomb they are sometimes discredited with being. Jacket loss: sometimes; bomb: no; good, deep holes: yes.
I would answer the original question differently if it had included something like a 358 Norma or 358 STA as a bullet launcher and we were talking thick timber. The 225 SBT should be plenty good for elk (or at least moose since I don't normally hunt elk) in the 358 Win, 350 Rem Mag, or Whelen cartridges at any probable distance though.