Originally Posted by iluv2viddyfilms
These are probably three of the most common automatic calibers to carry and I know this isn't the first time someone has asked to compare them. However I was curious as to the foot pound or jules produced by each caliber in the common factory loadings. I have a firearm in each of these calibers.
I went to wikipedia... and I'll accept it as a reliable source, at least for an online question and found the following:
9 mm 115 grain FMJ = 570 J and 420 foot pounds pressure.
.40 S&W 180 grain FMJ = 598 J and 444 foot pounds.
.45 ACP 230 grain FMJ = 561 J and 414 foot pounds.
So there really isn't much difference at all in energy expelled from the rounds. I know there's the old saying that speed kills which is why a relatively narrow .30 rifle round can do so much damage with the supersonic speed it produces - three or four times the amount a handgun round.
At these lower speeds does the size of the wound channel make the big difference in going with the .45 acp over the 9mm? I ask because if energy is what matters then you would think the 9mm would be a more effective round because it gives off slightly more kinetic energy.
I don't know much about ballistics but can anyone explain this or share their thoughts?
First, I'd like to point out that the numbers you are using are very skewed. The 9mm loading you list is 115 gr @ 1300. That is a VERY atypical 9mm loading. That's +P+ verging and close to .357 sig performance. If you want to go that route, there are +P+ versions of the .45 ACP called the .45 Super and .460 Rowland that get close to 44 Magnum energy.
Also, Wikipedia lists other 45 ACP loads that you didn't include such as the 185@1225 for 616 ft/lbs.
You were trying to match high-end 9mm performance with low-end .45 performance.
Anyways, real-world shootings say that there is not much difference between the major service calibers. I've always been a 9mm guy my entire life, and part of me still is. However, when I bought my first .45 about 6 months back the difference was apparent. The .45 slug did more damage to my target holders, hit steel targets with more authority, knocked bowling pins down easier, and cut larger holes in stuff.