Re: GURPS ULTRATECH ballistics?
Ok, so I decided to try an analyze the different approaches to damage values, muzzle velocity, Joules per gram of a given substance etc  all the while using both GUNS, GUNS, GUNS by Greg Porter and the spreadsheet that you devised, along with the formulas for what I used in order to that I could use specific real world data of bullet weight in Grains and bullet velocity in feet per second (how the data is displayed in CARTRIDGES OF THE WORLD 8th edition  I know it is at a higher edition than 8th as of today!).
So, here's what I did. I used both of Greg's formulas  Muzzle Velocity and Muzzle Energy, to double check against each other, and the original real values for any given bullet (the one I listed earlier with a bullet mass of 130 grains and a bullet velocity of 1180 feet per second).
Using your formula given on your spreadsheet, the Muzzle Energy for a 130 grain bullet travelling 1180 feet per second works out to 544.8475086 Joules. Greg Porter's formula gives a value of 541.9681402 Joules.
Using only Greg's formula for Muzzle Velocity (I didn't try to reverse engineer your formula, but I'd imagine if I did reverse engineer your formula, it would be slightly different than Greg's formula)...
(544.8475086/8.4238583)^.5 x 44.84 = 360.6181343 Meters per second or 1183.1304 Feet per second.
Using Greg's calculation formula for Joules in the equation:
(541.9681402/8.4238583)^.5 x 44.84 = 1180
So, it isn't surprising that using only Greg's formulas for Muzzle Velocity and Muzzle Energy will be internally selfconsistent in order to double check things.
Your formula for Joules is:
.5 * Weight in grams/1000 * (Velocity in meters/sec divided by 1000)^2
I'm guessing that you were trying to use the formula such that it used unit measures of Kg and Kilometers
That's my guess overall.
