There are different types of cartridges that are used for different purposes, such as self-defense, shooting, and competitions, to name a few. However, the never-ending or more than old-century debate between 9mm ammo and 45 ACP is persisting. Concerns like which cartridge is cost-effective, have more accuracy, magazine capacity, recoil, velocity, and so on are what keep on trotting in everyone’s mind while making a buying decision. Of course, personal preference plays a significant role in determining which head gun is best for you. To help you make a wise decision, we have prepared this guide for you, where we will walk you through the difference between 9mm ammo and 45 ACP. Without any ado, let’s start from scratch. 

Tracking The History Of 9mm Ammo And 45 ACP 

Before we dig into knowing why 9mm ammo is better than 45 ACP, let’s know the history of these two cartridges one by one below. 

9mm Ammo 

In 1902, German arms manufacturer George Luger originally designed and developed a 9mm ammo cartridge. He developed 9mm to improve previous pistol cartridges like the 7.65x21mm Parabellum. The same year, 9mm was introduced to the British Small Arms Committee. Then in 1904, the German Navy officially adopted this cartridge; since then, 9mm ammo has become a common preference for law enforcement and military use across the world. Thanks to its controllability, low recoil, and relatively inexpensive cost per round, which captured the attention of people who are into shooting, hunting, or want a cartridge for self-defense purposes.

45 ACP

In 1904, when the US government asked Frankford Arsenal and the Civilian industry to enhance their editing pistol rounds, Winchester Repeating Arms with Colt Manufacturing Company created 45 ACP. The cartridge was later designed by John Browning in 1905 with his M1911 semi-automatic pistol design. 45 ACP (Automatic Colt Pistol) is regarded to be the most powerful handgun rounds due to its amalgamation of stopping power and relative accuracy when fired at shorter distances. 

However, it has become popular over time due to its various uses, from self-defense to large-scale competitions like IPSC shooting matches. 

Let’s now jump onto the comparison between 9mm ammo and 45 ACP and know the reasons why 9mm is better than 45 ACP. 

9mm Ammo vs. 45 ACP: A Complete Comparison

Bullet Specifications 

The bullet diameter in 9mm ammo is 9.01mm (0.355 in), neck diameter is 9.65 (0.380 in), rim diameter is 9.96mm (0.392 in), rim thickness is 0.90mm and base diameter is 9.93mm (0.391 in). In contrast, 45 ACP comes with a bullet diameter of 11.5mm (0.452 in), a neck diameter of 12.0mm, a rim diameter of 12.2mm, and a base diameter of 12.1mm. 


Your ability to control the gun, especially when you execute shots consecutively, is defined by recoil. A gun’s recoil is known to be the backward movement a shooter feels when the bullet is fired from the gun. 9mm ammo has less recoil than 45 ACP, whose recoil feels heavier and pushes one’s hands backward rather than up. Also, it doesn’t have a muzzle flip that can reduce recoil and enhance the shooter’s experience while firing. So, recoil in a 9mm cartridge enhances accuracy, making it easy to handle the cartridge. 


What is velocity, you ask? Velocity is the speed of the bullet when fired from the muzzle of the gun. The simple rule in firing is that the more the velocity is, the better the trajectory will be (the bullet with higher velocity will go on a straight line than those with lower velocity). The velocity in a 9mm cartridge is between 990 and 1350 feet per second, while 45 ACP fires have an average velocity from 835 to 1150 feet per second. So, if you prefer long-range shooting, go with a 9mm cartridge for a better shooting experience. 


The penetration in the gun allows bullets to go through the thin material and damage opponents on the other side. 9mm has an average penetration between 8’’ and 15.9’’, while 45 ACP has a penetration between 11.3’’ and 14.3’’. So, using 45 ACP will eliminate the risk of bullets going via walls; therefore, it is suitable for home defense. Thus, 9mm might be more effective to use, but it may cause high damage due to its penetration. 

Power/ Ballistics 

The stopping power, penetration, expansion, diameter, grain amount, and gunpowder level of a bullet define the features and impact of its cartridge. Since 9mm is smaller and lighter compared to .45 ACP, it moves quickly and penetrates the target more deeply. In addition, its high velocity gives more stopping power to halt the bullet. In the case of .45 ACP, its heavier weight gives it less velocity, which means it won’t penetrate deeply. 

Price And Availability 

It is said that 9mm is cheaper than 45 ACP and is also more prominent in usage. In addition, 9mm bullet is also available in multiple variants such as hollow point, full material jacket, etc., at different price ranges. It can cost between 40% and 50% less than .45 ACP, making it the most cost-effective pistol centerfire round available today. 

Buy Premium And Cost-Effective Cartridges From Ammo Marsh 

Now that you have read the clear difference between 9mm and 45 ACP ammo, we hope you can make a wise decision. Whether you’re looking to buy a 9mm or .45 ACP cartridge, Ammo Marsh, a reliable online platform, is here to give you the cost-effective and quality cartridges you want. You can get every type of ammunition in our store, such as 30-30 ammo and 30-20 ammo for rifles, and 9mm bulk ammo for handguns and machine guns. You can surf our e-commerce store and buy the best ammunition you want.

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