The 9mm and the .45 ACP are two of the most recognizable handgun calibers in the world. Both have been around for a long time and are used by civilians, law enforcement, and military personnel alike.
But which is better? That’s the question we’ll be exploring in this article.
While both the 9mm vs 45 caliber are popular choices for self-defense, they offer very different characteristics. We’ll compare their stopping power, felt recoil, cost, magazine capacity, and their historical context to help you decide which one might be the better choice for you.
A brief history of the 9mm and .45 ACP
The 9mm and .45 ACP cartridges have long and storied pasts.
The 9mm
The 9mm cartridge was developed in 1901 by Georg Luger, derived from his earlier 7.65x21mm Parabellum cartridge. It was quickly adopted by militaries and law enforcement agencies around the globe, prized for its balance of manageable recoil, high capacity, and adequate stopping power.
The .45 ACP
Designed in 1904 by John Browning, the .45 ACP (Automatic Colt Pistol) was created specifically for the M1911 pistol. The .45 was intended to be a decisive “man-stopper,” addressing concerns about the effectiveness of smaller-caliber rounds in combat. The U.S. military adopted the .45 ACP, and it served as a primary cartridge in both World Wars, Korea, and Vietnam.
Specifications and dimensions
Here’s a closer look at the specifications for each type of ammunition.
9mm specifications
- Bullet diameter: 9.01 mm (0.355 in)
- Bullet weights: 115 to 147 grains
- Velocity: 950-1400 FPS
- Maximum pressure: 235.00 MPa (34,084 psi)
.45 ACP specifications
- Bullet diameter: .452 in (11.5 mm)
- Bullet weights: 185 to 230 grains
- Velocity: 700 – 1150 FPS
- Maximum pressure: 21,000 psi (140 MPa)
Ballistics and “stopping power”
The debate between the 9mm and the .45 ACP often boils down to the notion of “stopping power.” But before we go any further, let’s bust a myth: there’s really no measurable difference in stopping power between these two rounds.
The late Vincent J. M. Di Maio, a renowned expert in forensic pathology, put it this way: “…there is no appreciable difference in the effectiveness of the 9 mm and the .45 ACP cartridges.”
So, what does matter?
Ballistic gel testing is often used to measure a round’s penetration and expansion, and here’s what’s interesting: different ammo types within each caliber can produce vastly different results. For example, Hornady Critical Defense, Speer Gold Dot, and Federal HST are popular 9mm loads that perform well in ballistic tests. On the .45 ACP side, Federal HST, Hornady Custom, and Black Hills HoneyBadger are often highlighted.
However, the most crucial factor for effective stopping power isn’t the caliber, but rather shot placement. A well-placed shot with a 9mm is far more effective than a poorly placed shot with a .45 ACP.
Recoil and Handling
Let’s talk about how these guns feel when you shoot them. The 9mm generally has less recoil. That means it kicks back less in your hand, making it easier to control if you need to fire quickly.
The .45 ACP, on the other hand, has a more noticeable kick. The upside of a strong recoil is that it can contribute to more powerful impact on a target. However, greater recoil can make it harder to take accurate follow-up shots.
How many rounds can they hold?
In general, 9mm pistols hold more rounds than .45 ACP pistols. This is due to the smaller size of the 9mm cartridge.
For example, a Glock 17 (9mm) can hold 17 rounds in its standard magazine, while the Glock 21 (.45 ACP) holds 13 rounds.
Both calibers are commonly available, and there are many firearm options for both. You can find 9mm and .45 ACP pistols from brands like Glock, SIG Sauer, Smith & Wesson, Springfield Armory, and many others.
Cost and Availability
Let’s talk about price and convenience.
Generally, 9mm ammunition is cheaper than .45 ACP, and you’ll find it in more places. The popularity of 9mm means manufacturers make a lot of it, which helps keep the price down and the supply high.
Similarly, handguns chambered in 9mm are usually less expensive than their .45 ACP counterparts. If budget is a major concern, 9mm has a clear edge.
Self-Defense: Which is better?
Both the 9mm and the .45 ACP can be used for self-defense. Many people find the 9mm easier to control, and magazines tend to hold more rounds than .45 magazines. This can be a real advantage in a self-defense situation.
No matter which caliber you choose, you must train with it regularly. Practice is essential for developing the skills and muscle memory you’ll need to defend yourself.
Also, it’s important to choose ammunition specifically designed for self-defense. And, of course, shot placement is always the most important factor in any shooting scenario.
Frequently Asked Questions
Why does the military use 9mm instead of .45 ACP?
The military transitioned from the .45 ACP to the 9mm for several reasons. The 9mm is lighter, allowing soldiers to carry more ammunition. It also has less recoil, making it easier to control and shoot accurately, especially in rapid-fire situations. The adoption of the 9mm also aligned with NATO standardization, simplifying logistics and interoperability with allied forces.
Do police use 9mm or .45 ACP?
Most police departments today use 9mm handguns. While some officers may still carry .45 ACP pistols, the 9mm has become the standard due to its higher magazine capacity, lower recoil, and the availability of advanced ammunition designs that offer comparable stopping power to the .45 ACP. The 9mm also facilitates easier training for officers of varying sizes and strength levels.
Is the .45 ACP more powerful than the 9mm?
Traditionally, the .45 ACP has been considered to have greater stopping power than the 9mm due to its larger bullet diameter and heavier bullet weight. However, advancements in 9mm ammunition technology have narrowed the gap. Modern 9mm rounds can achieve similar levels of penetration and expansion to .45 ACP rounds, making the choice between the two calibers more nuanced and dependent on individual preferences and specific applications.
Putting It All Together
The 9mm and .45 ACP are both effective rounds, but they have key differences. The 9mm offers higher capacity, less recoil, and cheaper ammunition. The .45 ACP has a larger bullet diameter and greater recoil.
Which one is right for you depends on your individual needs and preferences. Think about your sensitivity to recoil, what you intend to use the firearm for, and your budget for ammunition.
The best way to decide is to visit a shooting range and try both calibers for yourself. This way, you can experience the difference firsthand and make an informed decision.