As I said in the beginning- Dorky engineers and math obsessed people are the ones that wax on and on about "energy". Not that there aren't some great engineers, there are, and I definitely need the math nerds because I'm not figuring out external ballistics without them....
However, it's ALWAYS those two groups that wax on and on about energy, and math, and equations and try non stop to justify their bs. In the end, we still have to shoot the bullets at different impact velocities into tissue simulate and correlate that with live tissue results to know what the bullet will do.
None of their equations give us any info, and is a huge waste of time, money, and resources.
Shoot bullets into properly calibrated tissue simulate. Measure. Done.
