Originally Posted by
Sosalty
Interesting to know that formulas often give more weight to velocity. Simple to X's weight and velocity and bet it's more representative of killing potential. Plan to weigh yotes in the future and continue to asses bullet/wound characteristics.
Kinetic energy varies exponentially with velocity. Ammo manufacturers like ke because foot pounds force seems like a measure of killing power.
As you noted, MOMENTUM, simply MV, is what really matters. Newton's law restrains that momentum is conserved, not energy, so it is a better measure of penetrating and killing power.
I generally use MV/7000, which converts grains to pounds, giving units of ft.lbm./s, a common momentum unit. These numbers will be single to double digit, rather than several thousand if you don't convert to pounds.
Another momentum killing factor is the Taylor KO factor. Simply momentum times bullet diameter. This is a gauge to compare stopping power of similar momentum bullets, with different diameters. MVD/7000=TKO The TKO factor helps explain why moderate loads out of a .45-70 seem to hammer deer even though a .30-06 has more energy.