I got tired of Googling every time I wanted to calculate muzzle energy. I would've bookmarked a site but I could never find one that was exactly what I wanted.
Instead, I found one that was close, modified it, and put it on one of my sites. You can try it out here:
http://www.vintagepistols.com
My little original contribution is something I call the "Handgun FMJ Knockdown Coefficient".
This Coefficient is calculated by multiplying energy in foot pounds by projectile cross-sectional area in square inches, and then normalizing the result so that standard Nato M882 9mm Ball ammo (0.355" diameter, 112 gr, 1263 fps) is equal to 100 on the scale.
This measure is a pretty good predictor of handgun "knockdown" performance when using FMJ/TMJ bullets. This would probably be useless for rifle bullets at a rifle velocities.
Don't rely on this as a predictor of cartridge effectiveness because that's impossible to predict (and I don't feel like going out and shooting a bunch of French goats). Penetration, expansion, and a host of other factor are, quite literally, left out of this equation.
I do believe it is useful though. By almost all real-world accounts, the .45 ACP ball cartridge is a better man stopper than the Nato 9mm cartridge. Yet, if you rely on energy alone, the Nato 9mm (112 gr @ 1263 fps - 397 ft/lbs of energy) has more energy than the old .45 (230gr @ 850 fps - 369 ft/lbs of energy). Therefore, energy alone can't be relied upon to predict "stopping power, so another factor must at work. I propose that in this case at least, "size matters".
Try it out and let me know what you think. (By the way, a typical 12 gauge slug is .729" in diameter and weighs 437 grains, and travels at 1300 fps).
Mods- Feel free to move this if you think it's in the wrong place.
Instead, I found one that was close, modified it, and put it on one of my sites. You can try it out here:
http://www.vintagepistols.com
My little original contribution is something I call the "Handgun FMJ Knockdown Coefficient".
This Coefficient is calculated by multiplying energy in foot pounds by projectile cross-sectional area in square inches, and then normalizing the result so that standard Nato M882 9mm Ball ammo (0.355" diameter, 112 gr, 1263 fps) is equal to 100 on the scale.
This measure is a pretty good predictor of handgun "knockdown" performance when using FMJ/TMJ bullets. This would probably be useless for rifle bullets at a rifle velocities.
Don't rely on this as a predictor of cartridge effectiveness because that's impossible to predict (and I don't feel like going out and shooting a bunch of French goats). Penetration, expansion, and a host of other factor are, quite literally, left out of this equation.
I do believe it is useful though. By almost all real-world accounts, the .45 ACP ball cartridge is a better man stopper than the Nato 9mm cartridge. Yet, if you rely on energy alone, the Nato 9mm (112 gr @ 1263 fps - 397 ft/lbs of energy) has more energy than the old .45 (230gr @ 850 fps - 369 ft/lbs of energy). Therefore, energy alone can't be relied upon to predict "stopping power, so another factor must at work. I propose that in this case at least, "size matters".
Try it out and let me know what you think. (By the way, a typical 12 gauge slug is .729" in diameter and weighs 437 grains, and travels at 1300 fps).
Mods- Feel free to move this if you think it's in the wrong place.
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