Formula to explain "knockdown"

A long time ago I read an article somewhere that had a formula or two that seemed to be a better explanation of on game performance than kinetic energy calculations. There was one that took into consideration sectional density for penetration and one that took into consideration diameter and how bigger calibers may have more "shock" than smaller faster bullets. In other words why a 45-70 is a better choice on griz than a .243. Is anyone familiar with these formulas or am I crazy. Thanks for any insight.

Why is a 30/30 a real life deer Killer ? Why is a 35 REM a black bear knocker downer ? A 7/08 does what a 7RM will do on elk, just as far?

After some cosmic interaction with the aliens from a culture far beyond our understanding I have been given the gift of knowledge from minds farrrrr greater than me.

SHHHHH ....(don't tell anybody). It's a fragile balance of bullet construction, velocity, game anatomy, shot placement and sometimes just d@mn luck.

But, mostly it's just putting an adequate bullet in the right place, the 1st time, as far as I'm concerned.

Gunner46 said it well, although I want pictures to prove the alien part.

I may have posted this before, can't remember, but I read an article years ago in Sports Afield. It addressed energy vs momentum. In short, it described how you can drive a very light bullet really, really fast and have high energy numbers that cause everyone to say "ooh, aahhh". But really makes the difference is what the bullet can continue to do once it impacts an animal. That's where the momentum comes in.

What makes the .45-70 a better choice on big critters compared to the .243 is the mass of the bullet having more momentum for better penetration. Think of what it takes to stop a large truck vs a small car. There used to be a good ballistic program on the internet that was easy to use and also listed momentum, but it went away. I have done minimal searching for another one, just because it's interesting, but haven't really found one that I thought was simple.

Ultimately a lot of bullets will fit the bill, both light and heavy. But again, as Gunner46 stated, it's a balance of a few different things.