From 9mm to .45 ACP: Breaking Down the Most Common Handgun Rounds

When it comes to choosing the right handgun caliber, the options can feel overwhelming. From the widely used 9mm to the hard-hitting .45 ACP, each round has its unique advantages and drawbacks. Whether you’re a concealed carry holder, a home defense enthusiast, or a casual shooter, understanding the differences between popular handgun rounds is essential for making an informed choice. In this guide, we’ll break down the most common handgun rounds, their history, performance, and best uses.

Why Handgun Caliber Choice Matters

The caliber you select directly affects stopping power, recoil, magazine capacity, and cost. While some prefer the lightweight recoil of smaller calibers, others prioritize maximum energy for self-defense. Your purpose—whether for self-defense, target practice, or duty use—plays a major role in determining the ideal handgun round.

The Most Popular Handgun Rounds Explained

9mm Luger (9x19mm Parabellum)

The 9mm Luger is arguably the most popular handgun round in the world. Originally developed in 1902 by Georg Luger, it’s the standard choice for many military, law enforcement, and civilian shooters.

• Recoil: Light and manageable, making it beginner-friendly.
• Stopping Power: Moderate, with good penetration and expansion when using modern hollow-point ammunition.
• Cost: Affordable and widely available.
• Best Use: Concealed carry, home defense, training, and competition shooting.

.45 ACP (Automatic Colt Pistol)

Designed by John Browning in 1904, the .45 ACP is known for its substantial stopping power. It was the standard U.S. military caliber for decades, famously used in the Colt 1911.

• Recoil: Heavier than 9mm, requiring more control and training.
• Stopping Power: Excellent, with large bullet diameter creating strong terminal effects.
• Cost: Generally higher than 9mm.
• Best Use: Home defense, duty use, and shooters who prefer a powerful round.

.40 S&W

The .40 Smith & Wesson was developed in the early 1990s as a compromise between the 9mm and .45 ACP. It quickly gained popularity among law enforcement agencies.

• Recoil: Sharper than 9mm but less than .45 ACP.
• Stopping Power: Higher than 9mm, with improved energy transfer.
• Cost: Moderate, usually between 9mm and .45 ACP pricing.
• Best Use: Law enforcement, self-defense, and shooters who want a balance of power and capacity.

.380 ACP

The .380 ACP (also known as 9mm Short) is a compact, lightweight round ideal for smaller pistols. It’s popular for deep concealment and backup guns.

• Recoil: Very mild, easy to shoot in small handguns.
• Stopping Power: Lower than 9mm; shot placement is critical.
• Cost: Slightly more expensive than 9mm due to niche demand.
• Best Use: Concealed carry in micro pistols, backup weapons.

.357 Magnum

The .357 Magnum is a revolver powerhouse introduced in the 1930s. Known for its impressive velocity and penetration, it remains a favorite for revolver enthusiasts.

• Recoil: Strong and snappy, requires good grip and training.
• Stopping Power: Extremely high; excellent penetration and energy.
• Cost: More expensive than semi-auto calibers.
• Best Use: Revolvers for self-defense, hunting, and wilderness carry.

.22 LR (Long Rifle)

The .22 LR is one of the most inexpensive and easy-to-shoot calibers available. While not ideal for self-defense, it’s excellent for training, plinking, and small-game hunting.

• Recoil: Virtually none—perfect for beginners.
• Stopping Power: Minimal; not recommended for defensive use.
• Cost: Very low, ideal for high-volume shooting.
• Best Use: Target practice, training, and small-game hunting.

FMJ vs. Hollow Point: Bullet Design Matters

Besides caliber, bullet type makes a big difference in performance:

• FMJ (Full Metal Jacket): Best for practice and range use. Offers reliable feeding but limited stopping power.
• JHP (Jacketed Hollow Point): Designed for self-defense, expands on impact to maximize stopping power and minimize over-penetration.

Caliber Comparison Chart

Which Handgun Round Is Right for You?

There’s no single “best” caliber for everyone. It comes down to your intended use, skill level, and firearm platform. For concealed carry, many prefer the balance of power and capacity offered by 9mm. If you want maximum stopping power, .45 ACP or .357 Magnum might be your go-to. Meanwhile, .22 LR remains unmatched for low-cost training and fun.

Always test a variety of calibers and bullet types in your handgun to ensure reliability and accuracy. Ultimately, the best round is the one you can shoot confidently and effectively.

Always follow firearm safety rules and check local regulations before purchasing or using ammunition.