9mm vs .45 ACP: Revisiting the Timeless Debate

What is the best handgun round?!?

The debate over the 9mm and .45 ACP is one of the most heated conversations in the firearms community.  Enough to spawn sayings you’ll see all over forums (and t-shirts).

9mm Will Kill Your Body, .45 ACP Will Kill Your Soul
9mm Will Kill Your Body, .45 ACP Will Kill Your Soul

Both handguns have a huge following thanks to their popularity and success in the field.

But which one is better?

Today, I’m going to cover some of the differences between the .45 ACP and the 9mm…which will hopefully help you make the right choice for your needs.

I’m sure this is going to spark plenty of debate, so please feel free to let me know how you feel in the comments.

Internet kid meme
Please be gentle in the comments.

Comparing 9mm vs .45 ACP

Let me start out by saying that the biggest mistake that most people make is taking a black-and-white stance on the .45 ACP and 9mm.

Handgun Caliber Smallest to Largest
Handgun Caliber Smallest to Largest

You’ll hear a lot of people say that the .45 is better because it shoots a bigger caliber bullet, or that the 9mm is better because of its capacity.  Click here if you want to learn about more handgun calibers.

Both are valid points, and very understandable reasons to prefer one over the other.

Even if you think size > capacity, or more bullets is more better, you have to admit having bigger bullets and having more bullets on tap are both worthy considerations when choosing one gun over the other.

.45 ACP primer close up
Is bigger always better? Some shooters think so.

The truth is…neither gun has a total advantage over the other one, and your personal preferences will play a lot in determining which handgun is for you.

Let’s take a look at the selling points of each one to help you decide.

About the 9mm

Praised for being compact and easier to handle than its .45 ACP counterpart, the 9mm has become one of the most popular rounds in the world.

For more than 30 years, the Beretta M9 and M9A1 have been the standard sidearm of the US Army, Navy, Air Force, and Marine Corps.

Beretta M9
Beretta M9

The Army is in the process of switching over to the SIG Sauer P320…but they’re still sticking to the 9mm caliber design.  

Sig Sauer P320
Sig Sauer P320

Even the FBI has phased out their .40 S&W sidearm in favor of the 9mm’s improved stopping power and penetration.

This begs the question: is bigger necessarily better?

Here are some of the advantages that the 9mm has over the .45 ACP:

  • It has a larger magazine capacity given a similarly sized firearm
  • Its compact nature makes it easier to carry, especially concealed carry
  • It has less recoil, making it an easier gun to handle – especially for beginners
  • The guns and ammo are significantly cheaper; sometimes as much as half the price
FBI Agents Target Shooting
FBI Agents getting some target practice in.

The 9mm also has a higher muzzle velocity than the .45 ACP because it uses lighter bullets.  This has caused a debate in the firearms community over what’s better, a fast and light cartridge or a heavy and slow one.

While the answer to this is up to debate, one thing is certain: higher muzzle velocity does equals slower bullet drop.

Something to remember when shopping around for a 9mm

One of the most attractive things about choosing a 9mm for home defense is having more rounds at your disposable.

Unfortunately, this benefit may be completely canceled out in some states due to magazine restrictions, so it’s a good idea to review any state and local laws before buying a 9mm if you’re set on having a 15+1 capacity gun.

Regarding the .45 ACP

From the days of the trusty Colt M1911 to modern .45 caliber handguns like the Glock G21 and the Sig Sauer P220, the .45 ACP has always been one of the most reliable calibers on the market.

Trio of 1911's
Trio of 1911’s

After all, it was the official sidearm of the United States Armed Forces during two World Wars, and remained so up until the 1980s.

Battlefield 1 M1911
You may have noticed it in every first person shooter game ever.

If you like the idea of shooting a gun with a lot of stopping power…you’re not alone.

Many handgun enthusiasts believe that bigger is, in fact, better and love everything that the .45 ACP has to offer. Here are some of its best features:

  • Its stopping power makes it a great home defense gun
  • Over-penetration isn’t as much of a problem with this caliber (see: big, fat, slow bullets)
  • Over 100 years of testing and iteration have produced some very powerful .45 ACP bullets

While slightly impractical, the .45 ACP also has the coolness factor on its side.  It’s a battle-tested gun that’s played an important role in American history during the 20th century.

shotgun meme with american flag guy
You’re welcome Europe.

Measuring the Two

There’s no doubt that the .45 ACP is a classic handgun that’s not going anywhere in the foreseeable future, but it just doesn’t outperform the 9mm.

Oomph

45 ACP Is For Grownups
.45 ACP Is For Grownups

Advancements in modern defensive ammo technology has helped the 9mm improve by leaps and bounds over the past 30 years; it’s not the same underpowered round that the FBI abandoned in the early 1980s. 

With a good modern defensive ammo, the 9mm is just as powerful as any .45, just in different ways.

Springfield XDS .45 vs 9mm
XDS in .45 ACP and 9mm Guns.com

When comparing the two handguns, it’s important to note that the 9mm hasn’t become better than the .45 ACP…it just caught up to it.  

Have a look at this video evaluating the stopping power and over-penetration of the 9mm and the .45 ACP.

Or a picture is worth a 100 words…new self-defense 9mm ammo opens up to create some nasty possible wound channels to stop attackers in their tracks.

147 Federal HST Expansion
147 Federal HST Expansion

Affordability

Furthermore, the 9mm is more practical for the average shooter looking to spend time on the range.

With boxes of 9mm Luger rounds being 30 to 40% cheaper than .45 ACP ammo, increased range time isn’t going to break your budget; and after all, spending more time on the range does make you a better marksman.  Here’s more tips on how to shoot more accurately.

However, there is always something to be said for having really big bullets ready to deal with really big problems.

Velocity

Also, for you suppressor enthusiasts out there, the .45 ACP is an inherently subsonic bullet.  It fires slow and heavy bullets at a lower muzzle velocity than the 9mm, and can be suppressed to near whisper levels.

HK45 USP with mounted light
HK45 USP with mounted light

Using your handgun in tactical situations

One of the main reasons why military personnel and many LEOs made the switch to 9mm handguns was because of the deeper bullet penetration.

Unlike in a home defense situation, the ability to shoot through a wall, automobile, or various other objects in a combat scenario can be the difference between life and death.

US Navy marksmanship practice
US military marksmanship practice with the 9mm M9

The FBI agrees that the 9mm has lifesaving features.

According to a report released in 2014, the 9mm was preferred in the field because of the following:

  • LEOs have a 20 to 30% accuracy rate in shootouts, so magazine capacity is important.
  • 9mm Luger rounds have a deeper penetration than other handgun calibers.
  • FBI agents have been observed to shoot faster and more accurately with the 9mm.
  • The wound tracks of a 9mm and a .45 ACP are almost the same.
  • The 9mm’s lighter recoil makes it easier for follow-up shots.

Considering all of the advantages of the 9mm, why would anyone want to use the .45 ACP?

Well, when it comes to home defense, the .45 ACP does hold one distinct advantage over the 9mm: shallower penetration.

Don’t worry, that’s a good thing here.

As mentioned in the video, over-penetration isn’t as big if a problem with the .45 ACP because of its slower, bulky bullets.

This means you have less of a chance of hitting an innocent bystander through a wall in a self-defense scenario.     

Choosing the Best Caliber for You

You might be wondering which caliber is better for you…the 9mm or the .45 ACP.

Well, this might rock your world but I’d recommend getting one of each.

Assuming you have the money. 

Guns for sale
“More guns” is the solution to a great many problems.

Many shooters like to have the .45 ACP for home defense.  It’s the perfect grab-and-go handgun to fire in close quarters where recoil won’t pose such a problem.

Alternatively, the 9mm’s stopping power and smaller design makes it ideal for open and concealed carry.  

While there are a number of compact .45 ACP models on the market, as a general rule, you can expect the 9mm to be more comfortable to carry in a holster.

Also, in a self-defense situation outside of your home, there’s a higher likelihood that you won’t be firing your gun at close range like in a home-defense scenario.

 In this situation, you’ll be glad that you have the faster follow-up speed and larger magazine capacity of the 9mm.

Settling 9mm vs.45 ACP

Ultimately, both guns are great weapons to have.  When choosing between the two, also consider which gun feels better in your hand.  

Some people prefer the heavier feel of a .45 ACP, while others find the light and slim nature of the 9mm to be more easy to use.

Lots of Holsters, Boondock Saints
Lots of Guns, Boondock Saints

Either way, the 9mm and the .45 ACP both pack a strong enough punch to neutralize any threat.

Where do you stand on the 9mm vs .45ACP debate?  Did I leave something out?  Let me know in the comments below!

34 Comments

  1. Over penetration should not be an issue. If you’re afraid of what’s behind your target you shouldn’t be shooting in the first place.

    1. Scenario: Armed burglar breaks in and is standing in the area in which your child/roommate’s facilities is now based behind him.

      Option one; You choose to have ammunition in your pistol that is know to over penetrate because why would you need a bullet that doesn’t fully penetrate something. Now you must shout for him to get down/leave, because your selected ammunition could possibly over penetrate and harm someone in another room, and hope the situation doesn’t escalate to him reacting in instinctive action by charging or shooting at you. This would most likely result in you firing at the assailant in a less accurate fashion as well as possibly harming others.

      Option two; You select a certain ammunition that has been proved to not fully penetrate. You fire at the armed person/s and take down the threat. The situation is now dissolved without any bystanders in the background getting injured.

      Most situations are going to involve you protecting/defending yourself with others in the background. If you conceal carry then there is a 90% chance of bystanders being in your firing line. Not every confrontation is going to be ‘range based’.

      1. Wrong, you change the angle. Drop to a knee which will angle your bullet trajectory upwards and if the rounds exit his body they should be travelling in a safe direction.

    2. The problem is you can’t always be sure of what’s behind your target in a defensive situation. In a self-defense scenario, you’re using your firearm because if you don’t, you or a loved one will be harmed. If you live in an apartment, or even a neighborhood, there’s no way to know what’s behind your target.

      FMJs go through wood, plaster, sheet rock, and most anything else in your walls like its nothing, so there’s no way to know what it may hit on the other side. Its not about hitting something or someone behind the assailant, it’s about hitting something through the wall and the garden fence behind the assailant.

      1. No one in their right mind willingly chooses to use FMJs in a pistol or rifle for self-defense. Expanding bullets passing through a bad guy should have little energy left, just don’t miss.

  2. Good show! I thought this was going to get way uglier in the comments. Thanks for the article, and for the mature comments.

    I’m carrying a 45, and it was because of the lesser penetration that I decided on it. But it’s like buying a vehicle, or picking out a new bass as far as there are pros and cons to each one. For me, it’s an SR1911, an old 4×4 Toyota with a stick, and a Pedulla…

    1. my choices on all 3 are exactly the same i thought that was oddly coincidental since all 3 are not the most common choices. Usually i hear 40 cal ford truck fender blah blah blah

  3. 9mm vs. .45. I say different tools for different tasks. If I am going mowing in bear country, my 1911A1 and eight FMJS are with me in case God forbid a bear attack.s. If I am passing through Welfareville and Methport on my way to the Promised Land, My TP 9 with 5 extra loaded 17 round magazines of 115 grain JHP will be with me. And if a Riot Festival ;looms, I’ll be riding in the back seat doing Green Beret carry of either my AK or AR, too. I want harm for nobody, and especially me and mine, too.

    1. I’m not sure 45 is a good choice for bear country, most folks choose a large caliber magnum revolver with bonded solids for that job. The rest of your post I am 100% onboard with!

  4. Today’s 45s aren’t that slow. The ones that I carry travel at 1000 fps. A big, fat, 230 grain hollow point at that speed will drop the MF faster than a 9mm any day of the week.. My state has a 10 round limit. I’ll take 10 “flying ashtrays” over the puny 9mm anytime.

  5. First; opinions are like, well you know, the hole on your back side. First mag size for home or personal defense holds no water! In the majority of the states, anything more than 2 rounds down range puts in in the pin for excessive force! With that being said it all lies on personal preference. The best home defense round of all time is a good old 12 gauge 2 3/4″ low brass #6 shot. It stops would be’s and penetration is a non issue. I prefer to carry a 45acp because it rips arms off bodies and a 12 gauge in the house.
    I would love to hear everyone’s thoughts.

  6. Which is best? Whichever caliber you shoot most accurately. I have pistols chambered in .22lr, 9mm Luger, .40 S7W, 357 SIG, and .45 ACP. Apart from the .22lr, I would consider using any of them for self-defense. My personal preference for a home defense handgun is a full-sized pistol chambered in .45 ACP. For mid-sized pistols I like .40 S&W which tends to cut the difference in capacity, ammunition cost, projectile mass, and muzzle velocity between 9mm and .45 pretty nicely. For compact or subcompact pistols I tend to favor 9mm due to recoil considerations in the smaller, lighter guns, and the magazine capacity limitations. I might possibly be able to shoot 9mm slightly faster but I seem to have consistently better first shot accuracy with .40 S&W and 45 ACP.

    1. I don’t think i would hesitate to use my ruger 1022 for home defense with modern rounds like stingers or velocitors the new browning rounds that go 1450 fps. i have used them on Coyotes and have seen the damage they are quite impressive. I would recon my 5 or close to 6 inch barrel Walther p 22 loaded with them with rapid shots would do okay . My father is a Doctor and interning in the E.R. His first patient was a guy shot right by the belly button. He didn’t make it and when they found the round it was in his neck. I realize these instances are rare but one things for sure i can cut a target in half with rapid shots so easily with a 1022 because of zero recoil i think i could shoot 4 rounds to 1 outta my 45. I am not sure if i would like to be hit by one 45 acp or 4 high velocity hollow point 22’s ( honestly i can say neither but i do not disagree just throwing my 2 cents in it is all about shot control and placement. Not always which round is bigger, faster, more powerful!!!!

  7. ERIC! (Pew Pew Eric) Keep the awesome info coming, I love your emails and love your site!

    Thanks for bringing our gun culture forward…

  8. Hmmm, always been a 1911 45cal chap,although 38cal is certainly better than 9mm which has been known to bounce off suspects believe it or not.Good article,interesting points!

    Thanks

  9. Having some experience with both calibers and owning every one you can name I would also like to mention body armor/bullet proof vest testing. A 9mm will sting ya but a 45 will break your ribs…. Just my two cents. Not that a low rent trash bag would be wearing a vest if he decides to break in your casa but with the cost of bullet resistant vests getting cheaper and cheaper any things possible. My advice is practice, practice, practice!! Muscle memory combined with good ole fashion “practice makes perfect” will allow you to drop a man in one shot and it won’t matter what you grab in the night! Except for maybe a BB gun!

  10. have the .45 pistol/carbine combo, luv ’em. practice once a month, and can do 6″ group at 8-10 meters with pistol… as far as pretty, get the desert camo… and I had money left over for ammo. Can’t go wrong with that.

  11. What is a “safer” 9mm ammo for home protection, one with similar (or if possible less) penetration risk vs. the average .45 ammo?

    I plan to soon buy a 9mm or .45.

    I love Eric’s articles. Well written, and no trash talking, rare in the gun world. Thanks, Eric!

  12. any lower powder grain ammo with a soft or no jacket on the led.. Most people I know use hollow points as they tend to have less penetration through walls and the human body but leave aone nasty show stopping wound…

  13. My first thought is: .45 is better because it’s bigger. As mentioned by another person’s comment above, any more than a couple of rounds down range may escalate the possibility of your prosecution, (Unless you are against multiple attackers.). Aside from that, aren’t they using the same bullet technology on .45 as they are on 9mm? Wouldn’t that make the.45 leap farther ahead again, in terms of “better”?

  14. I really admire the professional comments that was written. However, how about the hollow point bullets that’s suppose to stop and explode once they enter the body.Is that a myth or not? Please inform. What is the best Hollow Points for a Glock 19? .

    Thank You!

    1. Don’t know about explode, but a good hollow point will EXPAND. There are many good rounds for the G19 for social work. WIth that size gun/barrel you have lots of options.

      DoubleTap.com uses Speer Gold Dots and has some hot loads.
      Hornady has an XTP +P 135gr that is an excellent design.

      Some people carry a 124gr for summer and 147gr in cold climates where the BG might be wearing a Carhartt over sweaters, etc.

      BTW, I like the 9mm and .45 pretty much equally and have both calibers. For HD, I have a 12gauge but my G19 is fine. For CCW I’ll carry it in winter, then my G43 in summer and an LCP2 .380 BUG in my pocket.

  15. Call me crazy but home defense SCREAMS for a good ole Mossberg cruiser with a nice laser sight and maybe a strong, blinding flashlight for perps’ who go ‘bump in the night’ into your coffee table. It’ll take all kinds of enthusiasm away from your intruder whether you use choked turkey shot or 00. Less ‘intent’ to kill when LEO show up to take your statement and you’re less likely to injure a family member 3 rooms away! Also loud as hell – enough to alert everyone in the house and even if you miss, the intruder is less likely to stick around to hear the mechanics of a pump signaling a second shot is on the way whether they’re armed with a piece or a crowbar, unless they intend to harm you, rather than just steal your stuff.
    9mm in the field just makes sense, for all the reasons Eric lists plus those of you fine, well informed readers. Full sized .45 or .50 for when you really mean ‘permanent’ and final business and .300 BLK fmj rounds through a sbr (I know, tsk, tsk) or tactical pistola for 1200-1300 fps during a full blown war or zombie apocalypse! Will still have a long-range, full length rifle or carbine slung over my shoulder too…Why compromise when it comes down to multiple enemies wanting you dead or wanting to taste your brain? Talk about high-capacity magazines! Yes, I fully appreciate state round limitations (even if I don’t necessarily agree with them) so long as I have enough mags to hold out in such a life/death event., God forbid….
    Still, nothing like the feel of a nice heavy, ..45. customized to your liking as your arsenal ‘anchor’. Even better if you have the means and the skills to build one yourself, get to know what you’re shooting inside and out!

  16. What an awesome read. All the comments are great. It gives perspective from both sides. I carry both 9mm and .45 ACP (not at the same time.) It just depends on what I am wearing and how much concealment I want. I have a Sig 1911 Ultra Compact .45 and a Sig P938 9mm. The 9mm is super small and light weight (about 16oz empty) and the 1911 weighs almost twice that. The 1911 has a 3.3″ barrel and is also small. Both in MY OPINION have similar kick to them. I don’t want to carry anything bigger. I do take into consideration penetration behind what I am aiming at with the 9mm because of over penetration, but you must ALWAYS be aware of what is behind the perp. A shift to the right or left could clear the background behind them. It is always situational awareness no matter what.

  17. Here’s an old lady’s take on it: the best gun/caliber is what YOU shoot best.
    My “bedroom” gun (the one I keep ready for home defense situation) is a 1911 Gov. 45ACP. Why? Because out of all my handguns, this is the one I’m most accurate with. I don’t rely on the bullet (nor the sound of racking the gun, nor the sound of explosion to scare the intruder away). I rely on my skill to execute the shot.
    The best bullet will fail, if shot placement is poor. Next, speed of follow-up shots doesn’t come from the caliber. It comes from the shooter. It’s both in physical and mental ability. I’ll be shooting faster when I’m more confident that I can hit the target (the closer the distance; the bigger the target; the easier to handle, more accurate the gun…).
    And that’s why an old lady clings to her old 1911 🙂

  18. I carry a Glock 30 concealed . I prefer more shock per hit. I also carry the Ruger LC9 as a backup. I personally know of more more people surviving being shot with a 9 than a 45acp. Two were head shots. I’d prefer to hit with a slow moving baseball than a faster golf ball . But this is my decision. This debate of 9 versus 45 just comes down to personal choice with today’s ammo.

  19. Enjoyed the reasoned comments. Good show all. I was a die hard .45 fan but when I got the concealed license, it just wasn’t comfortable to carry. After some trial and error I did find a 9mm I was comfortable with and it concealed well. Like many others, I use the .45 at home (and in the car) with the primary at home a Mossberg Persuader. If you come into my home, they’re carrying what’s left out in a bag.

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