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Originally Posted by hal
The goal I think, is to get an "average damage value" which does factor in velocity squared. The divisor of 450395 is likely a conversion factor between imperial units and metrics. I'm going to have to find the original spreadsheet Doug gave me to confirm.

Likely. There are a lot of funky units at play here. Grains, grams, pounds . . .
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What I didn't understand in Doug's sheet were the metrics of 1/2 damage, etc and expansion of gases etc.
Hopefully, Doug himself will chime in on this, because I dimly recall I confirmed my formula with him before going with it...
Catch you in about 60 to 90 minutes

The 1/2D calculations used an exponential fall off of velocity based on sectional density. It's close enough to give a good approximation in the supersonic regime but isn't nearly as good as a real ballistics table.
the gas expansion stuff is just a representation of how much energy goes into the bullet, based on integrating force over distance. I used the ideal gas law to figure out how the pressure falls off as the volume expands (the volume is the chamber plus the barrel) and then just integrated Force = Pressure x bullet area over the barrel length.
Expansion is something I just plug into my penetration and wound channel equation  increase bullet caliber by the expansion ratio, and let the rest take care of itself.
For basic bullets thrown from ultratech guns, you're doing the right idea  take best guesses for caliber, mass, and velocity, and adjust mass and velocity so they're not crazytown and the damage is about right. The assumptions going into UT were not all rational and logical and if A then B, so it might not work every time.