Stopping Power

Which caliber has more stopping power?

  • .40 S&W

    Votes: 33 15.1%
  • .45 ACP

    Votes: 186 84.9%

  • Total voters
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Nov 24, 2006
I heard a question asked in a gun store today; "which has more stopping power the .40 or .45?", and the clerks answer was ".45".

I thought the .40 had more muzzle energy on average than .45 loads. Wouldnt that give it more stopping power? What do you guys think?
drgong that is a good point, but im not talking about which any particular person aims better, or even which is easier to control for follow up shots. just which cartridge hits harder (has more stopping "power")

Stopping power is much different than kinetic energy. Stopping power is more or less a myth, that's why you get answers like "which ever you can aim better with..." when a "stopping power" question is posed.

Which has the greater kinetic energy?

Well, physics says (ignoring coefficient of drag, which is reasonable for short ranges) that kinetic energy of a projectile is 1/2 mass x velocity squared.

With a 230 grain .45 acp load flying 900 ft/sec and a 180 grain .40 cal load going just 1100 ft/sec the math works out to about 1.16 times "stronger kinetic energy" for the .40 cal load.

Not a massive difference, but technically the .40 S&W has more kinetic energy at close range. The reason I voted .45 for stopping power is that .40 tends to penetrate really well (i.e. doesn't always translate all of its kinetic energy into the target) where the .45 (bigger and slower) tends to 'dig in' and deposit most of its kinetic energy into the target.
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Out of the gate this poll was a done deal.
Man of War against a second rate claimer!:D
I shoot a 1911 pretty good. Both of mine are pretty accurate.

Three different .40s at a gun range (indoors) one night sprayed rather than grouped.

Therefor my answer is .45!
If I hit a nail pretty hard with a 24oz hammer, or a little harder with a 22oz hammer, the only thing that matters is if I hit the head of the nail, because if I do, it's going to move.
Well I just compared JHP ballistics at the Remington website and at the muzzle the 185 grs. .45 had 411 ft-lbs and the 180 grs. 40 S&W had 412 so I'd say the .40. ;)

Of course if you're looking for ft-lbs though, the 40 S&W's best bullet on Remington's ballistics table was a 155 grs. JHP that offered 498 ft-lbs at 1205 fps.

The .45's best bullet was the Golden Saber 185 grs. Brass JHP. It delivered 534 ft-lbs at the muzzle at 1140 fps.

My conclusion is that I'd be happy with either since I don't have neither but my shooting skill requires me to lean towards higher capacity which means the 40 S&W.

I'm having a hard time deciding which one that I want for my next pistol. Even more so now. :banghead:
I chose .45 ACP

Mostly because I'm a loyalist.

Stopping power is a much used and much misunderstood term. I much prefer the term 'immediate incapacitation' because it comes with a definition. "Immediate incapacitation is defined as the sudden (2) physical or mental inability to pose any further risk or injury to others." (From PART 1 OF THE FBI PAPER ON HANDGUN WOUNDING FACTORS AND EFFECTIVENESS, July 14, 1989,)

In a self defense setting (which includes most of law enforcement encounters) one uses a firearm against an attacker to prevent that attacker from carrying out or finishing the attack.

Just what causes this is still under discussion. Grab a beer and a stump and sit down, this will be a while. The actual effect is argued, some say it cannot and does not happen. Others claim it does, but don't have proof of what causes it, unfailingly. Frankly, I think there are enough reports of people being shot and instantly 'freezing up' to believe it does happen. Nor, from the reports I have read and people I have interviewed, do I believe is it merely a psychological effect.

There are a couple of widely agreed upon factors.

One is bullet placement. The shootee has to be struck in the Central Nervous System or near to it. It must be noted a 'heart shot' will kill a person, but does not guarantee an immediate cessation of hostile actions.

The second widely agreed upon factor is energy transfer. Somehow the bullet must transfer the energy contained therein to the villainous individual that has driven us to the extreme measure of shooting him. (Or her, I don't want to be sexist here.) Not agreed to is the manner of such transfer. Some require a bullet to alter shape (expand) and use up all energy in stopping within the body of the target. Others believe a flat fronted, sharp edged bullet shape tears and distorts enough body mass to transfer energy. A third belief is that of dwell time, wherein the bullet moves so slowly it transfers energy to the target while transversing. (This last was the belief of the British War Department; their .380-200 revolver - a .38 S&W case launching a 200 grain RNL bullet at about 700 fps - gave stopping power much higher than presumed from the figures.)

Another widely agreed factor is sufficient power. The bullet delivered has to have a certain amount of 'oomphf' or 'horsepower'. What is not agreed to is what constitutes this sufficient power. Some folks posit kinetic energy as the secret weapon and some think momentum is the magic spell. (Just to save any guessing, I'm a momentum proponent.)

As I said, the argument lingers on. And on. And on.

I like big cross sectioned heavy bullets with flat fronts and sharp shoulders and a strong velocity.

The fact is, both .45 ACP and .40 S&W with decent loadings are pretty good defensive rounds. Now what the shooter does with them is another story.
I didn't vote in your poll because I chose not to answer the question.

However when choosing between the two rounds, I would look more closely at .40's because they generally have a smaller grip and fit my hand better.
I hate these threads but lets look at it from the wound channel POV. bullets are bullets and will expand perportionately to size. So 45 will expand 10% with a given a 40 will expand 10% with the same bullet. at .05 larger diameter the wound channel will be larger.

What I mean to say here is WHAT DOES IT REALLY MATTER? either will kill easily with shot placement!
* .45 ACP - 185-gr jacketed hollow point

* Success rate meeting 12" minimum: 92.5%
* Wound volume (cubic inches of tissue disrupted) 3.98
* Average penetration: 19.95
* Test barrel average group: 2.040
* Service weapon average group: 4.319

* 10mm FBI Load (.40S&W) - 180-gr jacketed hollow point [980fps]

* Success rate meeting 12" minimum: 97.5%
* Wound volume (cubic inches of tissue disrupted) 4.11
* Average penetration: 17.90
* Test barrel average group: 0.893
* Service weapon average group: 2.550

FBI 10mm Notes
SSA Urey W. Patrick, Firearms Training Unit
FBI Academy, Quantico, VA.

You decide.
sometimes you just have to let go of your instinct to drag accuracy into the picture and just answer the question.:banghead:
The idea of answering a "stopping power" poll to me is not much different than answering "Which is blue runted and twice chamfering the sliding portal tag?" I don't believe there is such a thing as "stopping power."

I believe in wound diameter.

I believe in wound depth and penetration.

I believe in shot placement.

I believe in follow-up shots.

I believe in muzzle energy.

I believe in gun, holster, and belt package that is comfortable enough for the owner to carry where ever his roads take him.

I believe in guns that afford the owner the comfort to practice with it frequently with a cost the owner can afford.

I don't believe in magic swords.

Show me a round that for the shooter mixes in fair amounts the things I believe in, and I'll show you the right defensive round for that shooter.
Here it goes again..... I'd rather have a perfectly placed .22LR than a .45 ACP
in the BG's elbow or forearm....... Shot placement is key!!!!! :banghead:
The 10mm Colt sidearm might not be an ideal long-distance weapon, and it's certainly no sniper's rifle, but it has the advantages of low weight and quicker target acquisition. You can reliably engage aggressors at ranges of 30 meters and more. Use a two-handed grip and brace the barrel against a tree, or use your dive tanks and rebreather as an improvised bench rest. Don't worry about "stopping power": One of those 10mm slugs opens up to about 70 caliber when it hits, leaving an exit wound you could toss a cat through, and bringing so much energy to a target that a hit in the extremities is often enough to drop Ivan in his tracks.
The 40 Is The New 357 Magnum

MODEL 4006,

My own agency went with the .40 S&W using the 155 grain JHP at 1160 feet per second. This load was developed for the U.S. Border Patrol, based on field experience with the .357 magnum. It has proven to be more effective than the 180 grain .40 caliber loads.

The experience of the old I&NS and now many other agencies is that this is as effective or better than the best .45 ACP loads. The Border Patrol gets a lot of field experience in gun fights on the southern border.
Since it was adopted back around 1997 or 1998, I have not heard a single complaint that it lacked stopping power.

Evan MARSHALL in his STOPPING POWER books rates this round at 94% or higher.

If you are looking for a load to carry, the big advantage of the .40/180 and 45/185 grain loads is not the stopping power, but the reduced recoil from the more powerful .40/155 and 45/200 & 230 grain loads. They are pretty much the same for stopping power.


p.s.---whenever someone on this BBS mentions MARSHALL'S work, there is an almost instant reaction by people who have a fanatic hatred to it. They will refer you to another site called "firearms tactical". It had little to offer when I checked it out, besides it non stop MARSHALL bashing.
Before following any recommendations, I would suggest you read both sides and judge for yourself.
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