Fascinating analysis Andy! Roger on the Joules, 850 Joules impacted on a lower limb is trumped by a broad arrow into a major artery. However I really like having a bunch of Joules in my holsterAndyC wrote:Well, knockdown power doesn't exist but for grins I calculated kinetic energies for these calibers, rounded up to 3 decimal places for easier reading:johncanfield wrote:I don't want to start a caliber war but I wonder how my EDC Sig P239 in .357 Sig compares to a .45 round in knockdown power? I do own a 1911 and it's one of my favorite shooters, dear wife enjoys it as well
230gr .45acp @ 900 fps:
230gr = 0.0149037 kg
900 fps = 274.32 m/sec
Ek = 560.763 Joules
115gr 9mm @ 1200 fps:
115gr = 0.00745187 kg
1200 fps = 365.76 m/sec
Ek = 498.457 Joules
125gr .357 Sig @ 1500 fps:
125gr = 0.00809986 kg
1500 fps = 457.2 m/sec
Ek = 846.564 Joules
Very impressive, huh? Not so fast. Let's take this object:
500gr = 0.0323995 kg
220fps = 67.056 m/sec
Ek = 72.842 Joules
Pretty weak, huh? Well... it's a 500gr broadhead arrow @ 220 fps.
As I've always said - ain't about the energy per se - it's how that energy is used to cause physical damage.
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