Agree on the thicker jacket on the 120, I've seen that photo and cross sectioned some myself...makes that bullet hell for stout.I personally like to keep my bullet energy a little higher on those longer pokes typically found with Elk hunting (just my opinion). More than one way to skin a cat, I suppose.
I get it, going a bit heavier isn't wrong...but IMO/E "energy" is grossly over-valued.
Some hunt, some shoot, some do both...per the photo: elk #1 70 yards, elk #2 230 yards, elk #3 120 yards. All one shot each.
What's the energy like on a .243 Winchester at 368 yards with a 100 grain partition?
I don't know either, but enough apparently to make a partition open up pretty well, and again IMO/E THAT is what matters.