There's some useful physics here: link
BTW, your estimate of 1500J tallies with my calculated energy of 66x 22.7J
I have a new respect for shot putters.
I've just looked up .45ACP and 9mm Parabellum and they are supposed to pack 450J and 583J respectively. I read that .45ACP has greater stopping power despite lesser energy due to its greater calibre. I guess that means your 7.5 cal 1500J projectile won't be lacking in stopping power.
Regarding the 9mm Parabellum and 0.45ACP it's like comparing apples and oranges, there are an abundance of non-truths out there, you can acquire cartridges for both with muzzle energies exceeding 700 Joules!
Although that is obvious dependant on your gun's barrel length and build quality...
Anyway "stopping power" is hard to define, because it's defined mainly by your target. For example trying to shoot someone who's wearing quality body armour in the chest with a 0.45ACP Hollow Point is as good as pointless, even with 700J of energy the worst you would do is break a rib. Now shoot them with a 9mm Parrebellum, of equal kinetic energy, with a soft-nosed - FMJ bullet and you'll do much more damage. Then try a 0.50BMG (>20,000J
) and you'll leave a hole in their back the size of an English football!
using these exact same bullets on a man who's wearing nothing but a T-shirt and jeans and the results will be MUCH
Just a couple of points, Sam. Most personal body armor is designed to stop normal handgun ammunition. Any personal body armor that won't stop 9mm soft-point is not worth owning, because that is currently the most popular caliber out there. I have seen the manufacturer of one of the most popular body armors shoot himself in the chest with a .44 Magnum, compared to which a 9mm is a girly-boy gun. Secondly, there is no such thing as a soft nosed FMJ. FMJ means "Full Metal Jacket". There are handgun rounds capable of defeating personal body armor, but they are not sold legally to civilians. It's also not that hard to make them, if you know how, and no, I won't tell you how to make them.