Comparison: 9mm vs. .45 ACP

Of all the topics subject to debate in the world of firearms, the one that probably receives the most attention is the debate of 9mm vs. .45 ACP.  While some would say that this debate has gone on for far too long, others will be quick to point out that choosing a personal caliber is a decision that can only be made after much thought and research.

The purpose of this article isn’t to claim superiority of one firearm caliber over the other, but rather to present the arguments for or against each one. After going over the basics and pros and cons of each caliber, we’ll delve further into specific categories and the advantages a particular caliber has over the other under each category.

This article isn’t for those who have already chosen a caliber for their pistol, rather, it is for those of you who are trying to decide and have narrowed your options down to 9mm or .45.  The important thing for you to know up front is that these calibers are currently the two most conventional ones in the United States and have been around for many years.  Neither of them is a bad round, and both will probably do what you expect them to.  However, if you’re still unable to decide, hopefully, the information in this article will be able to help you.

Let’s start by talking about the 9mm…

9mm

The 9mm Luger round has a total bullet diameter of 0.355 inches.  It was designed originally for use by the German military in 1902 for the Luger pistol, which was then to become their standard service pistol.

After that, the 9mm grew rapidly in popularity all over the world.  Countries saw it as a versatile, good all-round service caliber and had new military sidearms chambered for it, such as the Browning Hi-Power and Walther P38, both of which served in World War II.

The 9mm continued to become even more widespread after the Second World War, and eventually became the standard pistol round of NATO.  Today, the overwhelming majority of armies around the globe use sidearms chambered for 9mm.

The 9mm is also the most popular pistol round in the United States.  Not only has it found favor with law enforcement and the United States military (who use the round in the current standard issue Beretta M9 pistol), but it is also used heavily by civilians for concealed carry, home defense, target shooting, or by preppers for SHTF sidearms.

There are many advantages to owning a pistol chambered in 9mm.  For one thing, because of its immense popularity, 9mm is extremely easy to find and currently the cheapest pistol round to buy. These days, you can expect to buy a box of 50 rounds of 9mm FMJ for around the $10 to $15 range, which is around half the price of what you can expect to pay for .45.

Because of its smaller size, pistols can carry far more rounds of 9mm in the magazine in comparison to other pistols.  The Glock 17, for instance, holds 17 rounds of 9mm in the magazine.  The Canik TP9-series of pistols holds 18 rounds.  The Springfield XD-series holds 19 rounds.  You get the idea; double stacked pistols with 9mm hold a lot of bullets.

The 9mm is also easy to shoot with mild recoil, which makes it a great round to use in teaching new shooters.  The mild recoil also means that you can get multiple shots off quickly without being thrown off your target.

On the other hand, opponents of the 9mm will be quick to point out some disadvantages.  It has been claimed that the 9mm, at least in FMJ form, is lacking in overall stopping power and delivers less energy and wound size than .45 ACP does.

.45 ACP

The .45 ACP (Automatic Colt Pistol) round has a total bullet diameter of 0.425 inches.  This is a true American caliber as it was originally designed by John Browning for use in the Colt M1911 pistol; this reason alone is often what makes people grow so attached to it.

In its more than hundred year service life, the .45 has gained a reputation for being a so-called ‘one shot man stopper,’ with the idea that it can bring down a human sized target with only a single bullet.

There is no doubt that the .45 ACP is a great round of self-defense even in the form of FMJ ‘ball’ ammo.  The diameter is also substantially larger than the 9mm, which naturally creates a larger wound cavity or hole when striking a target.

Despite being a large round, recoil for the .45 is still generally relatively soft or mild.  While it has definitely got a larger kick to it than the 9mm, the .45 has gained a reputation by some novice shooters for being a high-kicking round, which simply isn’t true.

On the other hand, .45 does have its cons.  First and foremost, it’s more expensive than 9mm (nearly twice as much), so it’s not the best round for the budget conscious shooter.

Since it’s a larger round, this also means that pistols chambered for .45 typically carry less than those chambered for 9mm.  The 1911 holds just 7-8 rounds in the standard magazine, and even ‘high capacity’ .45 pistols rarely hold more than 12-13 rounds.  The FN FNX Tactical is currently the highest capacity .45 pistol in the market, at 15 rounds, and it’s a very big and bulky gun.

Still, there’s no denying that the .45 packs a wallop, which may make up for its low round count.  Next, let’s put the 9mm and .45 head-to-head in a few key categories and see how they perform:

9mm vs. .45

  • Bullet Penetration. Penetration between the 9mm and .45 is fairly even, though the 9mm has the slightest edge overall. In the end, it all comes down to the type of bullet you are using.  A 9mm round can have anywhere from eight to sixteen inches of penetration, while a .45 will have anywhere from eleven to fourteen inches.  Special loads made for self-defense of both calibers may have greater penetration overall, as there are some .45s capable of reaching up to nearly thirty inches and 9mms that can reach forty.
  • Bullet Expansion. The .45, being the larger bullet, wins this one, though again by a slight edge. A .45 can expand up to 0.75 inches on average, while the 9mm will expand to around 0.35-0.50 inches. However, certain self-defense 9mm loads can come closer to the .45 on bullet expansion.
  • Bullet Velocity. The .45 is a slow-moving round and therefore has less bullet velocity than the 9mm. The 9mm can fire between 1,000 to 1,350 FPS (feet per second), but the .45 will average around 800 to 1,150 FPS.
  • Capacity. In general, most full-size service pistols chambered in 9mm will hold anywhere from 13 to 19 rounds of ammunition in a standard magazine. Full-size pistols chambered in .45 will generally hold anywhere from 7 to 13 rounds.  Although extended magazines are available for both calibers that will increase total round counts.
  • Price. The 9mm is around half the price of a .45 ACP. Expect to pay $12-15 for a box of FMJ 9mm, and around $25-30 for a box of .45.  Special self-defense loads in both calibers will be more expensive.

Conclusion

Remember that, in the end, both 9mm and .45 are pistol calibers and therefore underpowered compared to rifle rounds. Also remember that shot placement, or where you shoot an attacker, is more important than the round used itself.  In other words, the differences between 9mm and .45 are fairly marginal when you look at the bigger picture.

In that regard, the debate between 9mm and .45 isn’t really a debate over which caliber is superior. People are still arguing over which one is better suited to the tastes of a specific shooter.  You may find that you see merits in both 9mm and .45 and decide to buy a pistol in both calibers.  After all, two is always better than one, right?


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4 thoughts on “Comparison: 9mm vs. .45 ACP”

  1. Good article. Alas, it’s a debate that will never end. At various points during my career I carried .the 357, 9 mm and 45 ACP. I’m old school so I do love my revolvers. But, as a dog handler I would carry a .45 in a shoulder holster when doing building searches due to the potential of a up close, oh shit moment. That .45 ACP 230 grain bullet gave me a warm and fuzzy feeling. That being said, I did like the magazine capacity and easy rolling recoil of the 9 mm. The 9 mm is the only handgun I carried for the last dozen or so years when I was a patrol Sergeant. I still own all of the above.

    Reply
  2. WITH THE NEW MORE ADVANCED 9MM ROUNDS THAT THEY HAVE TODAY
    IN HOLLOW POINTS
    THE 9MM HAS A BETTER CHANCE OF TAKING OUT AND ATTACKER NOW
    THE OLD 9MM AMMO BACK IN THE EIGHTH AND NINETY
    AND EVEN FURTHER BACK IN YEARS
    YOU HAD TO HAVE WAY MORE 9MM ROUNDS TO REALLY TAKE OUT AND ATTACKER
    THAN THE OLD 45.APC BECAUSE OF THE PURE KNOCK DOWN POWER
    THE NEW 9MM ROUNDS THEY HAVE TODAY ARE MUCH IMPROVED
    AS FAR AS MY SELF A CARRIER MY COLT 70 SERIES 1911 GOLD CUP. 45.APC
    AND I HIT WHAT I AIM FOR
    AND ALL IT TAKES IS ONE SHOT AND IT’S OVER
    AS WHERE THE 9MM EVEN WITH THE ADVANCED H.P. 9MM
    YOU MAY NOT TAKE A MAN DOWN WITH ONE SHOT
    UNLESS YOU HIT THE MAN IN THE HEAD ARE VITAL ORGAN
    AND YOU STILL MAY HAVE TO HIT YOUR ATTACKER WITH MORE THAN ONE ROUND
    I ACTUALLY KNEW A GIRL WHO WORKED FOR ME
    WHO WAS SHOT IN THE HEAD WITH A BROWNING HI-POWER 9MM HAND GUN
    AND SHE LIVED
    AND SHE WASN’T ABLE TO TALK FOR TWO YEARS
    THEN SHE WAS ABLE TO TALK AGAIN AFTER TWO YEARS
    AND SAID WHO SHOT HER AFTER NOT BEING ABLE TO TALK FOR TWO YEARS
    I REALLY LIKE SHOOTING THE 9MM IT’S FUN
    BUT AS FOR MYSELF I WOULD WANT MY COLT 70 SERIES GOLD CUP 1911 .45CAL
    ON MY SIDE
    BUT I KNOW PEOPLE WHO WOULD WANT THERE 9MM ON THERE SIDE JUST BECAUSE OF MORE ROUNDS IN THE MAGAZINE
    I GUESS IF A PERSON IS NOT THAT GREAT OF A SHOT
    THEY WILL WANT MORE ARE NEED MORE ROUNDS JUST BECAUSE OF THERE SHOOTING ABILITY
    AS FAR AS MYSELF I WANT TO KNOW THAT WHEN I SHOT MY ATTACKER WITH ONE SHOT
    THAT THE ATTACKER WILL 99% OF THE TIME
    WILL BE DOWN AND OUT OF THE FIGHT
    WITH THAT ONE SHOT

    BECAUSE A GUN FIGHT DOESN’T LAST BUT SECONDS ARE A FEW MINUTES
    AND IT’S OVER MOST OF THE TIME
    IT’S NOT LIKE THE MOVIE
    TO WHERE YOU NEVER RUN OUT OF AMMO
    HAHA LOL
    AND ALSO IN MOST GUN FIGHTS YOU’RE WILL BE IN VERY CLOSE QUARTERS
    NOT 50 TO A 100 FEET AWAY AND AGAIN NOT LIKE THE MOVIE
    SO ALL IN ALL I BELIEVE THAT IT WILL ALWAYS DEPENDS ON THE SKILL OF THERE
    SHOOTING ABILITY
    AND THERE OWN PREFERENCE
    IF YOU ARE A SKILLED MARKSMANS
    AND THE ONE SHOT YOU DO GET WILL MAYBE THE ONLY SHOT THAT YOU GET TO SAVE YOUR LIFE
    SO I BELIEVE THAT THAT ROUND HAS TO COUNT
    BECAUSE YOU MAY NOT GET ANOTHER SHOT
    AGAIN A GUN FIGHT DOESN’T LAST BUT
    SECONDS ARE A FEW MINUTES
    WITH MY. 45CAL ONE SHOT IS ALL YOU NEED TO TAKE A MAN DOWN AND OUT
    BUT WITH A 9MM THE ATTACKER MAY HAVE TIME TO SHOT YOU
    IF ONE 9MM ROUND DOESN’T TAKE OUT YOUR ATTACKER
    JUST ASK AND EMERGENCY ROOM DOCTOR
    WHO IS STILL BREATHING AFTER BEING SHOT WITH AND 9MM ARE A .45CAL
    WHEN HE GETS THEM IN THE HOSPITAL
    JUST A THOUGHT
    HAVE A VERY BLESSED DAY

    Reply
    • ” AND ALL IT TAKES IS ONE SHOT AND IT’S OVER”
      Please give an example of where you’ve personally experienced this? There is no such thing as a “0ne shot” handgun, its about shot placement and nothing more when talking about handgun rounds. Handguns don’t have the velocity to produce a permanent wound cavity through it’s kinetic energy transfer like a rifle caliber would.

      The author state correctly about the fps of both rounds. The threshold is 2200 fps concerning a permanent wound cavity, thus why the smaller calibers such as the 5.56 can cause such devastating wounds.

      Reply

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