Why doesn't the .45 look more powerful than the 9mm on paper?

[SIGfiend]

According to these data .45 is only a few foot pounds stronger than 9mm. If that is so why is .45 regarded as the more powerful "manlier" caliber??

.45 ACP
Ballistic performance
Bullet weight/type Velocity Energy
165 gr JHP 1060 ft/s
(~323 m/s) 378 ft·lbf
(~514 J)
185 gr JHP 950 ft/s
(~290 m/s) 371 ft·lbf
(~505 J)
230 gr JHP 850 ft/s
(~259 m/s) 369 ft·lbf
(~502 J)
http://en.wikipedia.org/wiki/.45


9mm
Ballistic performance
Bullet weight/type Velocity Energy
115 gr FMJ 1180 ft/s
(~360 m/s) 356 ft·lbf
(~484 J)
124 gr FMJ 1150 ft/s
(~351 m/s) 364 ft·lbf
(~495 J)
147 gr FMJ 1000 ft/s
(~305 m/s) 326 ft·lbf
(~443 J)
http://en.wikipedia.org/wiki/9_mm_Luger_Parabellum

 

[rantingredneck]

Because you're only comparing ft/lbs of muzzle energy which is not necessarily a predictor of "stopping power". Muzzle energy is calculated by a formula that puts an emphasis on velocity. 9mm is a high velocity round where .45 is a lower velocity round. Therefore on paper 9mm looks more potent.

In reality with modern high performance ammo either 9mm or .45 is a good choice for SD. Just don't expect a "one-shot stop" from either.

 

[Spartacus451]

The .45 load you are showing data for is extremely weak.
.45 defensive loads are close to 550 foot pounds.

 

[Sniper X]

Try using data from a 230gr JHP and see the light!

 

[Sistema1927]

Energy is only part of the equation. Penetration and diameter are other important factors.

 

[SIGfiend]

redneck, I was looking at foot pounds for the 'knockdown power' effect and it looks as if 9mm is only a few away. how can .45 be any better knowing this?

 

[Mainsail]

Compensation

 

[rantingredneck]

redneck, I was looking at foot pounds for the 'knockdown power' effect and it looks as if 9mm is only a few away. how can .45 be any better knowing this?

Because footpounds of energy is not the whole story. It is not a reliable predictor of "stopping power" in and of itself.

As Sistema said, penetration depth and bullet diameter (therefore diameter of wound track) count too.

As to "knockdown power" there is no such thing in a handgun cartridge. When shot with a handgun round you will not fly backward as if hit by the hammer of Thor, no matter what Hollywood would like you to believe.

That all being said. Using premium ammo 9mm and .45 are both excellent choices for SD. I own both.

 

[Buff51]

This is purely hearsay and highly unscientific, but I heard that Marines in Iraq prefer the old Government Model .45s over the Beretta 9mms because they can drop an enemy with one .45 round, whereas it takes two or three 9mm rounds to have the same effect. FWIW

 

[Southern Raider]

This is purely hearsay and highly unscientific, but I heard that Marines in Iraq prefer the old Government Model .45s over the Beretta 9mms because they can drop an enemy with one .45 round, whereas it takes two or three 9mm rounds to have the same effect. FWIW

Hardly surprising. When you are limited to ball ammunition, pick the bullet that makes the biggest hole to bleed through.

Even the energy numbers are BS with respect to stopping power. "Energy", from a scientific definition, is the capability to do work. Does the round in question rip up and destroy tissue, or does it pass through the target with 70% of it's velocity?

As previously implied, bullet design is by far the most important variable. One that most effectively uses the available energy to get to internal organs and rip them up wins every time.

 

[MK11]

".45 defensive loads are close to 550 foot pounds."

Which ones?

 

[mavracer]

buff51,
ya but they use fmj,not premium sd.
same thing happened over 100 years ago when we went from 45 colt to 38 spcl. wouldn't stop philipinos which is why we thankfully have our beloved 45acp 1911.

 

[mavracer]

".45 defensive loads are close to 550 foot pounds."
try www.doubletapammo.com

 

[bg226]

The energy levels are similar, but the .45 uses significantly heavier bullets.

 

[Gordon Fink]

Compared to many modern, standard-pressure loadings, the numbers from Wikipedia are a little low for .45 ACP and a little high for 9×19mm. That said, the difference still isn’t terribly large. Either cartridge would require multiple well-placed shots to quickly incapacitate a human target.

~G. Fink

 

[Bobo]

Bullet weight and size is also important. This is an extreme example, but...

What would you rather get hit in the chest by:
A bowling ball moving at 10 mph or a golf ball moving at 20 mph?

 

[Plink]

Paper numbers don't tell the whole story. In fact, they tell very little of it. A lot of folks are only interested in velocity and energy, but neither are a wounding factor in and of themselves.

The fact that there have been failures to stop with every caliber, and the perp absorbed hundreds if not thousands of pounds of "energy" is a big clue. The one thing all the failures have in common is that the bullet didn't hit anything vital. Getting a bullet deep enough into the vitals is the most important thing. Then comes diameter. The bigger the bullet when it gets there, the more damage is done.

A lot of folks will choose the lighter bullets for their increased velocity, yet with the reduced mass comes increase deceleration. A heavier bullet may have left the barrel slower, but can be travelling substantially faster than a lighter one after penetrating a few inches.

 

[lesjones]

The formula for muzzle energy is 1/2 times weight times velocity squared. Because you're squaring the velocity (i.e., multiplying it by itself) small increases in velocity create big jumps in muzzle energy.

Does that mean two loads with the same muzzle energy are equally effective? Probably not. Look at it this way. Using the same powder charge but changing the bullet weight, a lighter bullet will give higher velocity and therefore higher muzzle energies than a heavier bullet. Yet in each case you've got the same amount of energy (the powder charge) on the back end.

There's another calculation for momentum that is simply weight times velocity. The .45 looks much better when you look at momentum. Here's an example calculation showing .45 having about 35% more momentum than 9 mm.

(I used "weight" instead of "mass" above to keep it simple.)

 

[rantingredneck]

Thanks les. I knew that velocity was squared in the m/e formula but couldn't remember the rest and was too lazy to google.

 

[otomik]

Why doesn't the .45 look more powerful than the 9mm on paper?

Just put the paper downrange, fire a few rounds, bigger holes, that simple.

 

[DogBonz]

numbers are a little off

The Numbers for a 45JHP SD round should look a bit higher.

Other factors are that a full expanded 45 HP will measure almost 1 inch, where a fully expanded 9mm will hit about .6". This, in theory, means that it will leave a larger wound channel, and might give you a slightly larger “margin of error”. Someone once said “have you ever seen a target in a competition that was shot with a 9mm and the hole is almost touching the line for the next higher score, but didn’t cut the line, and you though man if that was a 45 it would have gotten the higher score? Well what if instead of a line on paper, that was a major artery in someone attacking you?”

I don’t know it that train of thought holds water or not, but it is interesting none the less.

All else being equal, both are good defensive rounds, and shot placement is key. Pick the one that you can shoot accurately and fast and train with it.

That said, my HD gun is a USP45.

 

[mavracer]

lets try a analagy
what happens when the slower 330# defensive lineman hits the much faster 230# running back.
its more than energy its also momentum

 

[HorseSoldier]

This is purely hearsay and highly unscientific, but I heard that Marines in Iraq prefer the old Government Model .45s over the Beretta 9mms because they can drop an enemy with one .45 round, whereas it takes two or three 9mm rounds to have the same effect. FWIW

Marines (or anyone else) who've put a bad guy down with either pistol are about as rare as hens teeth. There are some guys out there, but I'm calling urban myth on the claim. At least the premise it is based on real data or even personal anecdotal experiences involving shooting bad guys with both calibers of pistol. Now I'm quite sure there are guys (Marines and otherwise) who believe .45 hits harder than 9mm.

 

[Bula]

Just look at loaded rounds of each caliber. 45 ACP is quite a bit larger. Sure the 9mm is fast and capable, but that ol' .451" 230 grain ball sure is big.

 

[outofbattery]

It's the old "would it suck less to be standing in a crosswalk and hit by a Honda Civic travelling 55mph or a Ford F250 cruising at 40mph?".They both deliver a bunch of suck,just go about it a little differently.

Most supposed feats of .45 stopping power or 9mm's weakness are hearsay tales,they both work equally well or equally poorly depending upon how useful you think a pistol really is.