.40 vs .45: Which One Is Better For Self-Defense?

When it comes to picking a handgun cartridge for your carry gun or for home defense, you can’t go wrong with the 40 Smith & Wesson (S&W) or the 45 ACP.

Both cartridges have faithfully served shooters for decades. The 45 ACP cut its teeth in the trenches of WWI and served the U.S. Military faithfully all the way through Vietnam. On the other hand, the 40 S&W was baptized by fire in the concrete jungle by law enforcement officers (LEO), the FBI, and CCW permit holders starting in the 90’s all the way up to the present day.

However, many shooters find themselves in a dilemma when they decide to purchase a new semi-auto pistol: Which one is better? 40 S&W or 45 ACP?

In this article, we will take an unbiased look at each pistol cartridge and analyze all of the ballistics data, so you don’t have to! By doing so, when you waltz into your favorite local gun store to pick out your new self-defense handgun, you’ll know which one is going to best fit your needs.

What is the Difference Between a .40 and a .45? Let The Handgun Cartridge Debate Begin

The 45 ACP (Automatic Colt Pistol) is a rimless, centerfire, straight-walled pistol cartridge that was developed by John Moses Browning in 1904. After succeeding at military trials, it became the standard issue sidearm ammo for the Colt M1911 handgun. The 45 ACP fires 230 grain bullet at 830 feet per second (FPS) with 356 foot-pounds of muzzle energy per military standards.

The 40 S&W is a rimless, centerfire handgun cartridge that was developed in 1990 in a joint effort between Smith & Wesson and Winchester to satisfy the FBI’s needs for more effective defense rounds. The FBI initially adopted Lt Col. Jeff Cooper’s 10mm Auto for their new service cartridge but quickly discovered the recoil was too snappy for agents to handle. A reduced power load was developed that was the basis for the 40 S&W. Standard 40 S&W ammo fires a 165 grain bullet at 1130 FPS with 468 foot-pounds of muzzle energy.

Both cartridges are extremely popular for concealed carry, and with proper jacketed hollow point (JHP) ammo, will have zero issues stopping a bad guy in a self-defense situation.

But are the 40 and 45 the right choice for you, or should you go with a 9mm Luger, 357 Magnum, 10mm Auto, or 357 SIG?

In the following sections we will analyze the advantages and disadvantages of the 40 S&W and 45 ACP so you can answer that question.

Stopping Power

Since the dawn of concealed carry and the reliable semi-auto pistol, firearms gurus have been debating which caliber has the most “stopping power”. You’ll hear phrases thrown around like, “That 357 Magnum is a real man stopper!” Or “I only carry 45 ACP because it has so much stopping power!” Insert your favorite cartridge into the previous phrases to keep the handgun caliber debate going.

The concept of stopping power has never been quantified and is often thought of as a round’s ability to stop a self-defense situation.

A personal defense engagement typically ends in one of two ways:

  1. The bad guy gives up
  2. Incapacitation by blood loss or by lacerating critical internal organs

A bullet’s ability to sap an opponent’s will to fight is highly subjective. And as life is not a game of D&D, we cannot go to the local enchantress to apply a modifier to our handgun ammo to leech Constitution (roll 2d20 for critical hit).

If we are to believe that hitting an attacker hard enough will make them surrender, we can compare the muzzle energy of the 40 S&W and 45 ACP round.

Looking at the ballistics tables below, there is no significant kinetic energy difference between the 40 and 45. There are some loadings which perform better in certain terms, primarily those of the +P varieties, however, in general the muzzle energy for either handgun round is around 400 foot-pounds of force.

The 40 S&W generally fires lighter bullets at a higher velocity while the 45 ACP is slinging a heavier bullet at a slower FPS.

So, if muzzle energy is a wash between the two rounds, then it comes down to the capacity to wound an attacker.

The simple truth is that the 45 ACP fires a wider bullet diameter than the 40 S&W (0.452” vs 0.40”, respectively). Wound channels produced by jacketed hollow point ammo is superior to full metal jacket (FMJ) ammo. This is because the JHP will expand upon contacting soft tissue and the FMJ will not. You should always carry quality JHP ammo in your personal defense handgun.

When a hollow point expands, you should expect it to increase its diameter by 90-100%. This means that, under ideal conditions, your 40 S&W will open up to 0.80” and 45 ACP to 0.90”. That’s not a huge difference, but it IS different.

Sometimes, one tenth of an inch can make a difference between hitting a major organ and only causing peripheral damage.

And for that reason, I must give a slight edge in stopping power to the 45 ACP.


When considering a handgun round for your carry gun, recoil is important to consider because it affects follow up shots. The more felt recoil and muzzle flip there is, the longer it will take to get your sights back on target for another shot.

Every shooter would love to have a handgun cartridge that has the felt recoil of a 9mm Luger with the power of a 357 Magnum. Sadly, you can’t have your cake and eat it too when it comes to recoil.

Normally, you would expect the round that fires the heavier bullet to have more recoil, however that is not the case for 40 vs 45.

Many shooters report the 45 ACP as having less recoil than the 40 S&W. This is because 45 ACP rounds typically fire at subsonic velocities (under 900 FPS) and have lower overall chamber pressure than the 40. This leads many fans of the 45 ACP rounds describing the recoil as a push.

As the 40 S&W is simply a 10mm Auto lite, the 40 has considerably higher chamber pressure and fires its 165 or 180 grain bullet at a much higher velocity than a 45. This combination creates what many shooters describe as an incredibly snappy and sharp felt recoil similar to a 357 SIG.

Considering recoil is extremely important if you plan to concealed carry a lightweight subcompact sidearm. Smaller handguns will absorb less recoil and therefore transfer more energy to the shooter’s wrists. For example, a shooter will experience less recoil when shooting a full-sized Glock 21 or Colt 1911 when compared to a subcompact Glock 30, Springfield XD-S, or Beretta Nano.

As the 45 ACP is loaded to a lower pressure, it gives it the edge in terms of having less recoil and allowing for faster follow up shots.


The FBI did extensive ballistics gel testing after the 1986 Miami Shootout to evaluate handgun defense rounds. They determined that a self-defense cartridge should have reliable expansion with 12-18” of penetration to be considered effective.

And when it comes to penetration, you want to shoot the heaviest bullet weight with the highest FPS that can be handled. A heavier bullet traveling at higher velocity will carry more kinetic energy and allow it to penetrate deeper.

In terms of the 40 S&W and 45 ACP, there is not a lot of difference in penetration between JHP ammo. However, the 40 will typically penetrate a little deeper due to its higher FPS than the 45.

When a hollow point expands, it prevents over-penetration and causes additional damage to the bad guy. Therefore you should NEVER carry FMJ ammo in your self-defense sidearm, because a FMJ will not expand and will likely exit the bad guy and potentially harm an innocent bystander or damage private property.

Quality jacketed hollow point ammo such as Winchester PDX-1, Federal HST, or Speer Gold Dots have been proven by law enforcement agencies across North America to provide excellent penetration and terminal ballistics.

One final thing to consider is that self-defense ammo is typically loaded a little hotter than FMJ practice ammo. This is to ensure that the hollow point has enough FPS to penetrate deep enough to stop a bad guy.

Ammo companies will often load practice ammo a little lighter as it saves them money, and also makes for a more enjoyable shooting experience for the end user.

As such, you should always shoot at least 1 magazine of your defense rounds through your carry gun every time you go to the range. This way you are used to the increased recoil and FPS you’ll experience when shooting full power jacketed hollow point ammo.

And if you need excellent penetration and muzzle velocity, the 40 S&W will be the right choice for you.


Accuracy is a difficult category to quantify as it is mostly dependent on the shooter’s skill level and the shooting platform they are using.

Most shooters will report that they have better accuracy with a cartridge that has less felt recoil. That suggests the 45 ACP would be the better choice for accuracy. However, I know several LEO’s that are nothing short of a surgeon with a 40.

A handgun cartridge with higher recoil will sometimes cause shooters to flinch, either out of surprise from the firing of the pistol or in anticipation of recoil. A flinch will throw rounds off target as the shooter will disturb the sights before the bullet leaves the barrel.

What it comes down to is practice and trigger control. A marksman with solid shooting fundamentals and trigger control will have no problem achieving exceptional accuracy with their sidearm and handgun cartridge of choice, regardless of recoil.

All things being equal, the 40 and 45 are very accurate cartridges and there should be little to no difference between them. However, many shooters report better accuracy with the 45 ACP, which is likely due to softer felt recoil.

Magazine Capacity

Law enforcement shooting reports indicate that sidearm accuracy suffers when officers are put under stress.

How bad does it get? The numbers would suggest accuracy is around 20-30%, which means most shots fired actually miss.

As such, you want to bring as many handgun rounds as you can to ensure you can stay in the fight longer.

As the 45 has a wider bullet diameter, it will take up more space in the magazine. For example, a standard Glock 21 magazine can hold 13 rounds of 45 while a Glock 22 magazine will hold 15 rounds of 40.

In terms of magazine capacity, the 40 is clearly the superior choice.

Concealed Carry/Home Defense

When it comes to home defense, my choice is the 45 ACP because I want a heavier bullet that can more likely stop an attacker or would-be home invader sooner, with as few shots as possible. The Winchester Ranger-T JHP would be my choice of ammo for this role.

For home defense, handgun weight is less important, and I would actually recommend a full-size semi-auto pistol as the added weight will reduce felt recoil. A Sig Sauer P220, Ruger SR1911, or Glock 21 would fill this role perfectly.

When it comes to concealed carry, handgun weight is a bigger issue.

Now some CCW permit holders will scoff at weight and carry a full-size Springfield 1911 Range Officer all day long, and to that I salute your commitment. However, it’s a lot more comfortable to concealed carry a subcompact polymer-framed handgun like a Glock 27 since it’s so much lighter.

When you’re out in the concrete jungle, the two main factors to consider in caliber selection is magazine capacity and penetration.

When you are out of your home, you are limited to the number of bullets you can carry on your person. Therefore, a higher magazine capacity is preferred when you concealed carry.

Furthermore, depending on the climate you live in, there is the possibility you will have to engage a threat through multiple levels of clothing. Fabrics, especially denim, are notorious for slowing down bullets and clogging hollow points and decreasing their effectiveness by inhibiting expansion.

Taking all these points into consideration, the 40 makes more sense for CCW as it has higher magazine capacity and will penetrate deeper than a 45.

Bottom line: 45 for home defense, 40 for concealed carry.

Ammo and Handgun Cost/Availability

The three most popular handgun calibers in North America are 9mm Luger, 40 S&W, and 45 ACP. As such, ammo for 40 and 45 is plentiful and diverse.

When it comes to cost, the 40 is the cheaper option at the time of writing. On average, practice ammo will run you around $0.50/round while FMJ 45 rounds will hit your wallet around $0.60/round.

Premium self-defense ammo like Winchester Silvertip or Speer Gold Dot 40 S&W will put you in the area of $1/round, while a box of 45 ACP Federal HST will deliver pure stopping power at $2/round.

In terms of semi-auto handguns, the sky is the limit as there are numerous options for each caliber. As these are two of the most popular handgun cartridges, virtually every manufacturer has some offering for both. Ruger, Glock, Springfield, Kimber, Smith and Wesson, Taurus, CZ-USA, Beretta, and Sig Saure all have multiple pistols in 40 and 45.

When it comes to cost the price between 40 and 45 is typically inconsequential when dealing within the same line. For example, a Springfield XD 40 will be about $20 less than a XD 45 (based on MSRP).


If you enjoy rolling your own handloads, then you’ll love the 45 and 40. There are a wide variety of powders and bullets to choose from to make your perfect practice ammo.

Reloading for both calibers is very simple and very rewarding at the same time.

If, however, you are reloading for an older model Glock 40 cal, please be aware of the “Glock bulge” that can cause a potential failure point in your brass cases.

To read more about the Glock Bulge and how to handle it, Click HERE.

Continue reading .40 vs .45: Which One Is Better For Self-Defense? at Ammo.com for comparative ballistic data!


Ha ha! I carry a 9mm, so chew on that! Never had a 40, went from .45 to 9mm for the round count and the modern ammo, and because I shot one in competition.


I carry for the most part a 40… but I use hot Underwood ammo no matter what I am carrying…
I went from a 9mm to 40 because of the weight and power (foot pounds) increase. 45 just doesn’t have the capacity I am seeking and for the most part, the firearms are larger and heavier.
Weight and capacity have a major factor with me.
My G19 with a 17 round magazine weighs the same as my 3 inch barreled Ruger SP101 with 5 rounds. Guess what I carry hiking?
Yep… the 9mm
I only own 2 45 caliber handguns. I canot tell you off the top of my head how many 40 or 9mm pistols I own.
But I can say, when push cones to shove, the 45 stays home and a 40 or a 9mm comes with me.


Love my 40s. Have 3 of them. 2 CZs and a Sub2K for the briefcase. I am going to get a 22LR Kadet slide for the 75B, already have one for the P-09, and 9mm for both of them. I actually will get a 40 Glock to go with the Sub2K for mag compatibility. I don’t see a need to add a Sub2K in 9mm, but you never know…

If I ever pick up a 45 caliber, it’ll most likely be a wheel gun. A 1911? Maybe, but I will build it as a double stack.


Spray ands Pray is the only reason for a high round count.
The average round count in a self defense situation is 2 rounds.
The alphabet LEOs went back to 9mm from 40. hmmm.

Modern 45ACP ammo is hotter than mil spec ammo.
The box of store bought I keep is 230gr @ 1050fps. (cant shot bad guys with reloaded ammo in this state, for the reason listed above.

So I make all my reloads right around 1000fps. I reload both FMJ & cast.
I use only Blazer cases, so I can use small primers (same as the woman’s 357 mag). We reload them like black powder cartridges. No space inside the case. 100 yards shot are doable, try that with a 40 or 9.

When my daughter decided she want to learn handguns, shot shot her boyfriend’s 9mm. When she came to our ranger she wanted to fire the mighty 45ACP.
Ive been shooting 45ACP since I was nine years old. I would call that a bias.
Whom ever said getting a wheel gun in 45, that would be 45COLT, not ACP. Whole different animal.
After shooting several magazines she asked ‘Is there a 46’


Damn it!

Why do we have to read to know which one is better!

Just tell us, we’ll believe you :grin: :grin: :grin:


I disagree.


Yeah, the military is considering a single shot breech loading .45/70 for their new rifle.


Yer Slayin’ Me :rofl: :rofl: :rofl:


They’re both good. We’re just splitting hairs.


I have 1. 40cal and several 45’s. Usually carry my compact Kimber 45 or my 9mm Glock.


The lack of training money was one of the factors when police started going away from revolvers, over penetration was another.

Yet the cops have no problem trading in their shotguns for ARs.

Well they will out distance an AR, and you only need one shot, for one kill.
Sure glad I have a 1895 Marlin. (lever guide gun for the one that didnt know that)


Ummm… wasn’t your whole arguement for AR15s over leverguns chalked up to capacity? I believe you quoted your wife whom said leverguns are for playing John Wayne and 30 vs 6 is the only reason one needs to go with the AR.


I wholey disagree that a 9mm and a 40 cannot go 100 yards. We shoot out to 200 yards quite frequently with both and screw around at 300 yards.
I can say this… do not be on the other end of my 9mm at 200 yards. At 150, you can be running even…
And while most encounters only pop off 2 or so rounds, that is not all encounters.
Look at what happened to BJ Baldwin when the 2 thugs tried to take him out. He ended up stopping the use of Hornadey ammo.
(Only one if many reasons I only use Underwood)
Like I stated before, I will pack my G19 over my SP101… weight, round count… 5 rounds of .357 V 19 rounds of 9mm… and yes, that is +P+ ammo.
Here is my other major issue with 45 ACP as compared to 40, or 9 for that matter… size.
Sure, there are platforms out there that will handle a +P+ 45 ACP round. Like Glock…
But that gun is so fricken big, I may as well just run the exact same size in a 10mm… (oh wait… I do)
This is where I would change my mind. Ball ammo…
If we could ONLY shoot ball ammo, I personally think the 45 has the edge. Well, until we need to penetrate obstacles… then the 40 or the 9… cars and homes have a magic way of stopping a lot of slower, larger rounds.


Check out MAC new video where he tells the world a shotgun is useless for home defense and we all need to go out and spend $4000.00 on a B&T setup that is suppressed with an Aimpoint. :rofl::rofl::rofl::rofl::rofl:
He himself contradicts himself and repeats the over all issue with EVERYTHING and that is training. Or, lack there of.
I do not know of any instances of the average Joe getting into a full on battle inside his own home.
I’m sure there are some specific times… like a Crack house or equivalent… or maybe somewhere outside the US and there is a hard core attempt on someone’s life.
But… once hot things start flying through the air, most bad guys are on the run.
That being said, there are some… like myself… that are targets. Why? Because we have what others want.
So… me carrying a double stack is in my options a necessity. I can no longer count that I will be up against only one… and only need 2.5 rounds to end a conflict.


I watched the video.

For years I suggested shotguns to others. But I agree with many of his comments on shotguns for home defense and I no longer suggest them. I just didn’t produce a video and I came to the conclusion that my bullpup shotgun was going to stay in the safe. But I tried to fix the problems first.

I selected a bullpup to keep it short and prevent it from being levered out of my grip. I’d have to claim success there. To counter the slow to load I planned on using short shells (1 3/4" ?). In testing I got one malfunction. It was probably me that produced it but if I produce it in testing what will happen when the SHTF? So I shelved the entire idea.

Previous to the shotgun my HD gun was a 16" AR with a can. But again, I didn’t like the length.

Backup a bit in time… 3 years ago we had a cop killer running around in the backyard and I found a long rifle to be just too unwieldy as I went about doing chores. That started me on short firearms. Around the same time I started to shoot a 9mm PCC in competition and my choice was a B&T GHM9 with a red dot. Would it be an excellent HD gun? Absolutely. Would I suggest it for most folks? No, due to the expense. But today it remains my comp’ gun. Short is still important, and the shotgun remains benched and I wanted more ft/lbs than the 9mm. So I built a 300BLK handgun that wears a can all the time and I load it with special ammo that won’t over penetrate. Sure, I can fire it shouldered, but that makes it a bit too long (again) and reduces my control of it. So I plan on using it tucked under my arm and pulled back. A light/laser is my aiming solution when used that way.

What would I suggest to a new buyer wanting a HD firearm? Probably an affordable PCC with a red dot. Ruger makes a good one, I’ve heard good things about the Beretta Storm, the KelTec folder I shot in competition was reliable and inexpensive, there are probably others. I’d also school the user on not clearing ones own home, but stay put in a safe room and let the cops clear it. That removes the length issue. But that’s a whole nother subject.


I just think it has limitations but obviously it’s plenty capable. I will counter MAC with Clint Smith’s videos

“Sympathy falls between sh*t and syphilis in the dictionary.”

  • Clint Smith

@RogueGunnWorks I like Underwood loaded Gold Dot 165 40SW the best.

Here is good read by a interesting guy. Skip to the end and read his CV, not your average MD…

His feelings pretty much reflect my own.


Of course shotguns are capable and have been for a very long time. Of course a case can be made for them. But that doesn’t mean they are right for everyone in every circumstance. Thankfully we have plenty to choose from today.

Obviously they’re not for MAC under the conditions he set out. Not for me either, a personal decision the reasoning for which I stated. I certainly never said they weren’t capable. I can’t remember MAC stating that either. Maybe he did though since I jump forward in videos to skip “filler”. If the 1 3/4" shells worked in my shotgun it holds 11 slugs and that would have been plenty. Since they are low recoil and relatively low velocity I would have kept the bullpup shotgun in the role of main HD gun. After testing them for over penetration that is but I never got that far.

Nothing I ever want to do, but I’m getting ready to clear my own home. I can foresee circumstances happening where I’ll need to. But it is something that’s very low on my bucket list of things to do. Short guns are better at it IMO. When the cop killer was in the “back yard” I went to a bullpup and it was so much better for doing chores outside. It would also be great for house clearing, but what I have now is so much better for my circumstance. Maybe not for everyone.

Ridgewalker, The .40 will definitely do the job also. But so will a proper 9mm round or a .45 ACP. They all need to be placed properly and a proper bullet selected. Scumbags typically buy the cheapest 9mm to be found and that’s 9mm ball. That could be why the guy with the bandana was so cheerful. It’s a terrible stopper. Why our military chose it boggles the mind (political decision and not because it’s the best for the troops).

The problem I have with handguns for noobs, which is what MAC stated over and over though he didn’t discuss handguns, is that noobs think they’re easy to use and have no clue that they require constant training. Yet they think a handgun is best for HD. Case in point, my sister in law. She wanted a handgun for HD. So she bought a .380. I strongly suggested she train with it with a professional trainer since she is NOT a gun person. That hasn’t happened yet to my knowledge. Her idiot son who is a Sgt on a police force and another non gun person loaded it for her and that was the extent of the “training”. She doesn’t even know how to unload it. But she has a handgun to perforate the walls of her home if someone gets in and scare them away with loud noise. I did suggest a PCC to her and that too was ignored. Right now she has a handgun that’s loaded but has no clue how to use and hasn’t fired it even once. Good move! I did suggest that she get her idiot son to unload it for her, I don’t know if that was ever done. It wouldn’t surprise me if he talked her out of it.


I agree with most of that,I am not a shotgun gun guy just playing devils advocate here.