Over the years, the firearms industry has seen remarkable advancements, with manufacturers continually producing innovative pistols to meet the diverse needs and preferences of enthusiasts. Despite all the technological improvements seen in handguns today, one facet has remained unchanged: their caliber options.
Two options stand tall amongst the rest: 9mm and .45ACP. Both cartridges were developed over 100 years ago, and yet they’re still the top choices for many. Each one has garnered a substantial following as both have proven their effectiveness—but that begs the question, which is best?
Make no mistake, both 9mm and .45ACP are fantastic pistol calibers, however, they each come with their own distinct advantages and considerations. Follow along as we go more in-depth on the intricacies of each cartridge.
9mm vs .45 ACP: Ballistics and Performance
To truly understand the differences between these two calibers, it’s important to look at how they compare ballistically. The main difference in their ballistic performance stems from their differences in velocity and mass.
9mm cartridges utilize smaller, lighter projectiles that usually weigh anywhere from 115 to around 147 grains, which can reach velocities between 1,100 and 1,300 FPS, depending on the load. Although smaller than .45 ACP, modern 9mm rounds deliver a solid amount of kinetic energy onto a target.
In contrast, .45ACP fires a significantly larger bullet, weighing anywhere from 185 to upwards of 230 grains. These rounds travel a lot slower, with their velocities ranging from 800 to 950+ FPS. But despite their slow speed, the additional mass of these projectiles delivers a substantial amount of kinetic energy to a target upon impact.
Recoil and Accuracy
Recoil is another crucial factor to consider whenever you’re selecting a pistol caliber. Compared to .45 ACP, 9mm has a softer recoil impulse thanks to its smaller size and powder charge. This not only makes 9mm pistols easier to control, but it also allows you to more accurately make rapid follow-up shots when needed. .45ACP produces much more recoil due to its heavier bullet and larger powder charge. This isn’t to say that .45 ACP is unmanageable, but to a new or otherwise untrained enthusiast, it can be difficult to wield.
Both calibers are remarkably accurate, but their performance differs when different distances are considered. Between the two, 9mm has a flatter trajectory, giving it an edge when shooting at further distances, while .45 ACP experiences more drop off due to its heavier weight and slower velocity. Keep in mind, at average pistol shooting distances (25 yards and back), you likely won’t notice much difference in accuracy, if any at all.
9mm Pistols vs. .45 ACP Pistols
The firearms market offers a wide range of options for both 9mm and .45 ACP enthusiasts, with almost every major manufacturer producing pistols chambered in each. Between the two, 9mm is the most popular caliber, and as such, there’s a wide selection to choose from. Models like the GLOCK 19 and 17, SIG Sauer P320, and HK VP9 are some of the most popular and common models available.
Although not as popular as 9mm, there are a plethora of solid .45 ACP handgun options available too. Models like the GLOCK 21, FN 545, and traditional 1911s continue to be popular choices for those who prefer the power allotted by .45 ACP.
Before you start shopping for a new handgun though, it’s important to understand the differences these pistols have. Like we said before, 9mm and .45ACP differ significantly in diverse ways, and as such, the handguns that use these pistols do too.
Size and Ammo Capacity
While the size difference of 9mm and .45 ACP is clear when comparing the rounds themselves, this difference becomes even more noticeable when comparing their respective pistols side-by-side.
Generally, 9mm pistol models are more compact and lighter than pistols chambered in .45ACP due to the smaller size and diameter of the 9mm round. Conversely, .45 pistols are larger as they must accommodate for a much larger cartridge diameter, making them heavier and bulkier in the process. Compact .45 pistols do exist that are better suited for concealed carry; just bear in mind that they often come with a smaller magazine capacity.
In terms of ammo capacity, 9mm handguns often have higher standard capacities. Compact to full-size 9mm models can store anywhere from 15 to as much as 21 rounds, while sub-compact and select micro-compact pistols can store anywhere from 7 to 15+ rounds. .45 pistol models tend to hold much less. Compact and full-size models usually hold around 8 to 15 rounds, with smaller compact models storing anywhere from 5 to 8 rounds.
If you’re looking to maximize your pistol’s round count while maintaining a compact size, 9mm is the move. For example, SIG Sauer’s P365 X Macro is a micro-compact 9mm pistol that has a standard capacity of 17 rounds despite being only 1.1 inches wide, which is slimmer than most compact pistols. The FN 545, which is slightly larger with a 1.45-inch width, has a standard capacity of only 10- to 15-rounds, depending on the model. So, if ammo capacity is a top priority for you, 9mm is the better choice, as some of the best sub-compact 9mm pistols options boast high capacities.
Weight Differences
Lastly, weight is another crucial factor to consider. Like we said before, .45 ACP often uses anywhere from 185- to 230-grain projectiles which is very heavy compared to 9mm which ranges from 115 to 147 grains. Similarly, 9mm pistols are almost universally lighter than their closest .45 counterparts, simply due to the size.
The lighter weight of 9mm pistols and ammo make them easier to wield and easier to carry over long periods of time, which is one reason they’re so often recommended for women and new enthusiasts who might not want to be wearing heavy leather gun belts every day. Our guide on guns for women highlights some other key considerations and insights into what all you should look for when selecting a new pistol.
1911: 9mm vs. .45 ACP
It’s difficult to talk about .45 ACP pistols without bringing up the 1911. Developed over 100 years ago, the 1911 is still one of the go-to pistol models enthusiasts often associate with .45 ACP. Today, they’re still produced by a wide array of manufacturers, and while they were originally designed to chamber .45 ACP, there are many available chambered in 9mm as well.
Pros and Cons of 9mm and .45 ACP 1911s
When comparing 9mm and .45 chambered 1911s, the same considerations we mentioned in the prior sections apply as well. 9mm 1911s are some of the best single stack 9mm pistols available, offering light recoil impulses and comparatively higher standard capacities of around 8 to 10 rounds. .45 ACP 1911s have higher recoil and anywhere from a 7- to 8-round capacity depending on the model.
Traditionally, 1911s utilize a steel construction, which can make these pistols weigh up to 2.5 pounds, at times. There are many modern models that use aluminum frames instead of steel, but they can still weigh up to 1.5 pounds or more. These heavier weights make the recoil impulse much softer when shooting 9mm. While there will be noticeably more recoil when shooting a .45 1911, they’re still easy to control, albeit quite heavy when loaded.
Much like for the other pistols mentioned above, choosing between a 9mm or .45 ACP 1911 primarily comes down to your personal preference. You can’t go wrong with either option, but it’s important to research each choice carefully before buying to make sure it’s a proper fit for you.
Self-Defense Considerations: 9mm vs .45 ACP
Terminal Ballistics and Expansion
Both 9mm and .45 ACP have many different defensive hollow-point ammunition options available. Comparatively, hollow-point .45 ACP ammunition offers the greatest amount of expansion upon impact. .45 hollow-points can expand up to an inch, or more, in diameter, while 9mm hollow-points expand to around .5 to .75 inches. Additionally, the design of 9mm bullets allow them to penetrate deeper into a target, with 9mm meeting all of the FBI standards for penetration depth. Despite this difference, both calibers are a solid choice for personal protection, offering solid expansion.
Shot Placement
Regardless of whether you opt for 9mm or .45 ACP, even the best-performing ammunition will be ineffective if your shot placement isn’t on-point. One of the core features enthusiasts often look for in a defensive caliber is their one-shot effectiveness (stopping a target with one shot). While many assume that .45 ACP has the advantage due to its size and expansion, various testing performed by the FBI and other Military/Law Enforcement agencies have shown that where you place the shot matters more than the size of the bullet.
While you can’t go wrong with either choice, 9mm has the distinct advantage of a greater standard capacity and reduced recoil, making it more useful whenever multiple targets are present. .45 ACP, while effective, doesn’t have as high a round count on average—and in high-stress environments, the added recoil can make achieving repeated accurate shots even more challenging.
Regardless of which caliber you choose, it’s paramount to make sure that you train regularly with your handgun. Regularly heading out to the range and incorporating dry-fire drills at home will reinforce the fundamentals of shooting while also building reps for better muscle memory.
Conclusion
9mm and .45 ACP have long been the two of the most popular pistol calibers available, despite both cartridges being designed over 100 years ago. Each one offers comes with its own distinct pros and cons, and they need to be carefully considered before choosing one over the other.
To sum them both up, 9mm is favored by many for its lighter recoil impulse, higher magazine capacities, and higher velocities. On the other hand, .45 ACP offers considerably larger bullets and greater expansion when using hollow-point ammunition, albeit with the caveat of higher recoil and lower ammo capacity, at times.
For personal and home defense, both options are a solid choice, but we usually recommend going with 9mm for simple practicality. Of course, if there’s a .45 pistol that you shoot especially well and feel confident with, don’t be afraid to pick the tool that gives you your best performance.
And if you’re on the fence about which pistol is the right one for you, our guide on the best pistol for home defense will point you in the right direction.
