Rimfire vs. Centerfire What You Need to Know – Foundry Outdoors

Rimfire vs. Centerfire What You Need to Know

For those who are just getting into firearms, one of the first things to consider is caliber. You might have heard terms like rimfire and centerfire, but what does that mean?

Most rifles, shotguns, and pistols use a centerfire cartridge which means they have a primer in the center of the back of the casing. Some cartridges, often smaller, use a rimfire casing. That means that the priming compound is distributed in the rim on the back of the case. Let’s dive further into this and find out what you need to know about both kinds of cartridges.

Case Configuration

Centerfire cartridges consist of a primer in the center of the back of the cartridge. The firing pin hits the primer in the back and ignites it, thus making the cartridge fire. Centerfire cartridges are the most common and can be reloaded using at-home reloading presses.

Rimfire cartridges are simpler than Centerfire cartridges. Rimfire cartridges have a priming compound in the rim of the cartridge. The firing pin inside the gun strikes the rim to ignite it and make it fire. Rimfire cartridges cannot be reloaded as the priming compound is part of the casing, not a separate primer.

Common Rimfire Cartridges


The .22LR (Long Rifle) is not just the most common caliber of rimfire; it’s the most common caliber in the world. The .22LR is a very versatile cartridge and can be used for casual shooting, competition, small game hunting, and even self-defense in very specific applications.


The .17HMR (Hornady Magnum Rimfire) is a newer caliber that is commonly used for target shooting, small game, and even some smaller medium-size game such as raccoon and fox.


The .17HM2 (Hornady Mach 2) is an updated and even faster version of the .17HMR. (NOTE: A gun chambered in .17HM2 will not fit a .17HMR OR vice versa)


The .22WMR (Winchester Magnum Rimfire), commonly referred to as a 22, is essentially a .22LR cartridge with a much larger powder load. The .22 Magnum is used for small to medium-sized game, plinking, and target shooting. Overall, .22 Magnum ammo is less common and more expensive than the .22LR with over double the muzzle energy.

The muzzle energy of a bullet is the kinetic energy of the bullet as it leaves the barrel of a gun.

Common Centerfire Cartridges

With a few exceptions, most of the other calibers you are familiar with are centerfire cartridges. Here are a few of the more commonly thought about centerfire cartridges

Centerfire Rifles

5.56 NATO

The 5.56 NATO is used by the United States military and is commonly used by civilians for varmint hunting, self-defense, and competition shooting. Perfectly adequate for taking medium-sized game such as fox and coyote.

.308 Winchester

The .308 Winchester, also known as the 7.62x51mm NATO, is another rifle cartridge used by the US Military as well as being used by civilians for hunting medium to large game, self-defense, long-range shooting, and competitive shooting.

Centerfire Pistols


The .9mm is a very common caliber used by civilians, military, and law enforcement. It's commonly used for concealed carry, target shooting, and home defense. The United States Military uses the 9mm for it's sidearm, and has for over 30 years, going from the Beretta M9 to the SIG Sauer P320.


Much like the 9mm, the .45 ACP is a very popular handgun caliber for both civilians and law enforcement. It's used in a multitude of different firearms but it is possibly made most famous for its use in the Colt 1911 which was used in both world wars by the United States. Though it has since been retired from standard issue, it is still used by some special forces operators.

Centerfire Shotguns

12 Gauge

The 12 gauge is the most popular shotgun caliber in the world. It is most commonly used for hunting, home defense, and competitions. It is made in a variety of different loads for different uses, such as birdshot for small game (rabbit, squirrel, dove, etc.) and buckshot and slugs for larger game (deer, wild boar, etc).

20 Gauge

The 20 gauge is the second most commonly used shotgun caliber. It is also used for hunting, home defense, and competitions. It is less powerful and is lighter than the 12 gauge. It is also easier to shoot with less recoil, both of which make it very popular with young shooters, women, and those looking for a quicker follow-up shot.

Why The Military Uses Centerfire

During the Civil War, most soldiers would have carried a caplock muzzleloader, like a Springfield Model 1861. However, some lucky cavalry soldiers were issued a Henry Repeater, chambered in the Rimfire .44 Henry. This was revolutionary in the day as it allowed a much faster rate of fire than the standard 3 rounds a minute of the muskets. Later, in 1875, Colt released their 1873 Single Action Army which was also chambered in .44 Henry.

As revolutionary as these guns were, they had a few flaws, mostly reliability issues. Rimfire cartridges were prone to not firing or igniting when dropped. It was clear that a change was needed. In 1873 the Trapdoor Springfield chambered in 45-70 was introduced, a centerfire cartridge, and they haven’t gone back. From the 30-06 Springfields and M1 Garands to the .556 M16s and M4s, the military has used centerfire rifles as general issue since then.

So Which Should You Get?

It completely depends on what you're trying to do with your firearm. Are you looking for a good starter gun to learn on, plink, and target shoot with? Maybe even some small game hunting? A .22LR (or one of the other rimfires) might be your best option. If you're looking for a home defense gun, or maybe something to shoot longer distances or hunt large game? A centerfire is definitely the better way to go because of the smaller sizes that most rimfires offer.


Foundry Outdoors is your trusted home for buying archery, camping, fishing, hunting, shooting sports, and outdoor gear online.

We offer cheap ammo and bulk ammo deals on the most popular ammo calibers. We have a variety of deals on Rifle Ammo, Handgun Ammo, Shotgun Ammo & Rimfire Ammo, as well as ammo for target practice, plinking, hunting, or shooting competitions. Our website lists special deals on 9mm Ammo, 10mm Ammo, 45-70 Ammo, 6.5 Creedmoor ammo, 300 Blackout Ammo, 10mm Ammo, 5.56 Ammo, Underwood Ammo, Buffalo Bore Ammo and more special deals on bulk ammo.

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