Well I have to update the post above about the Hornady 170 gr SST bullets.

I was wrong. I thought both bullet were lost in the gut-pile. Not so!
Today I butchered the elk and I found both of them. The one that hit the liver did penetrate the 2nd lung and exited upwards. I found it under the internal membrane of the chest cavity resting against the spine. It weights 129.2 grains.

The one that hit the pelvis was found in the right flank of the bull about 2 inches from the impact point of the other bullet. The bloodshot area I assumed was from the one that hit the liver, but some of it was from this bullet.
All that was left was an empty jacket that now weighs 45 grains.
Here are the 2 bullets and one that I cut in half so we can see the internal part of the jacket.

So this bullet did a bit better than I first thought. It is going to be excellent for any game up to about 300 pounds and will suffice for game up to maybe 900 pounds.

I will likely use a 180 Gr GMX next time because I know it will hold together, or maybe the 200 Gr Nosler Partition. The 170 gr will shoot flatter I know, but the 200 Gr Nosler is 100% reliable even when it hits bone. If I had only this 170 Gr bullet for my 8X57 for the rest of my life I am sure I would feel ok about it, ----- but if I can get the 180 Gr GMX or the 200 grain Nosler I think I may be a bit better off.