Song Dogger,
I'll offer my thoughts on the 300/180 combo for elk and other game. My wife shoots everything with her 300WSM, with 180 TTSX's at 3015 fps, has for years. This includes everything from 70lb hogs, a 65lb blackbuck, lots of deer at 150 - 275lbs, a 300+lb nasty old boar, and a 900+lb kudu. Her longest shot has been 406 yards to date and the bullet performance on all animals has been as expected. Even on the smaller creatures we've had good expansion and clean quick kills. We've only recovered 2 of the 180's from her kills. One from her kudu bull which was shot at 110 yards, quartering to, slightly downhill. The bullet entered right above the near shoulder knuckle, broke ribs going in, pulverized the lungs and arteries above the heart, broke the last rib on the far side and was stopped by the skin. All the petals broke off that bullet, but that made no difference to the bull as ran 70 yards and piled up. The second bullet we found was on a 180lb hog sow that she brained face-on, found the bullet with one petal missing in the right thigh. I think her most prolific example to the 300/180 combo was our biggest hog at 300+lbs that hit quartering slightly forward at 234 yards, that bullet had a tiny entrance and tiny exit wound and went through both in the plates at nearly 1 inch thick, but everything inside was destroyed, I literally just scooped the lungs out of that one.
So my personal preference is heavy-for-caliber bullets, 180's in the .308, 168 in the 7mm, 200 (TSX) in the 8mm, and 225 in the .338. The one overiding factor in my personal opinion is the ensure the impact velocity is appropriate for the bullet/cartridge combo. I've read that the impact velocity for the TTSX is 1800 fps, but we've never even come close to that number, (lowest impact velocity we've calculated is approx 2100) and have had good results.
Once again, if you're planning on shooting game over 600+ yards, this may not be the best bullet for you. But under that limit, we've been very satisfied.