I think that better than just identifying the 77TMK as being top draw the greatest benefit of this thread is that it has confirmed and validated with data the usefulness of a whole range of heavy and not so heavy projectiles that are almost as good as each other on deer. And some wishful thinking and isolated examples on other large game species which I think based on my large deer experience is pushing the envelope a bit.
There seems to be a sufficiently large pile of elk posted in this thread that I think we're beyond the level of isolated examples in respect to that particular breed of ungulate.
IMO the value of the bear and moose reports is not so much in what they say about the suitability of 77 gr TMK for hunting bears and moose - I would prefer a larger bullet myself, though I wouldn't begrudge someone for choosing otherwise - but rather as a 'sanity check' for species such as elk and black bear. A bullet that performs so well on an animal the size of a moose or brown/grizzly, even given our small sample size, is very likely to be reliable on anything substantially lighter. In my mind, data points from hunts involving the target animal itself (that being elk I'm talking about here) and larger, tougher game (brown bears, moose) are more useful for evaluating the suitability of a bullet for the target animal than extrapolations from animals that are smaller.
And as far as simple self defense from the aforementioned larger animals goes, I think it probably provides pretty good validation there too.
I will add that the 75 Hornady BTHP seems to stay together well and slightly mushroom or tumble upon impact. Every deer I have shot with it has had a 1 to 2 inch exit hole, instant blood trail, and has died within 30 meters. Everything I have shot with them I have gotten complete pass through.
77 SMK seem to frag out more. This is consistent with their historical performance in ballistic gel, animals, and humans. You typically get 4 inches of straight penetration, then a violent yaw, and the bullet breaks apart at the cannelure and frags out. Massive damage. Almost too much but very effective.
From what I remember of standard 75 gr Hornady BTHP testing, it typically performs a bit better than 77 gr SMK. A slightly shorter neck, maybe a little more frag, bit more consistent.
I wonder if the 75 gr Hornadys are not producing similarly large holes inside the body cavity, and you're observing smaller exits because the bullet frags earlier and thus the wound cavity also narrows down sooner?
What are the go to powders for the 77 TMK? I can’t find XBR 8208. What are some comparable, preferably temp stable, alternatives? I saw someone using Varget and some recommending TAC.
If you're willing to use factory ammo and skip the loading process, I believe Black Hills 77 gr TMK is available from a number of online retailers right now. I can't speak as to the exact properties of their proprietary powder blend but it seems to be some very efficient stuff; the primers from the fired brass have been some of the roundest I've ever seen.
On the downside, Black Hills no longer seems to be putting case and mouth primer sealant on their 77 gr TMK lots anymore. Bit of a disappointment but it is what it is.