Boxers or briefs? The real question is Boxer vs Berdan primers. Every new shooter should know the difference between the two and whether one is better than the other. So, we’ll start with the quick answer and if you’re interested, we’ll dive deeper into the details from there.

Berdan vs Boxer

Berdan primers have a double flash hole with an anvil built in to the casing. Boxer primers have a single flash hole with an external anvil. There is no real difference in terms of performance and your firearms can shoot either type of primer. If you are a reloader, you’ll likely want to stick with Boxer primers as the single flash hole design is easier to reload.

What is a Primer?

Box of winchester primers

The primer is the part of a cartridge that turns a trigger pull into an explosion.

A primer contains a small amount of pressure-sensitive chemical. When the firing pin crushes it, the primer creates enough heat and sparks to ignite the propellant or powder. The very first primer was the match in a matchlock rifle. When the trigger was pulled, the match would be lowered into the chamber that held the powder, and presto! This now seemingly simple design would forever change the world: With a primer, you don’t need to wait on a fuse.

The past few centuries introduced a number of primers: wheellock, flintlock, caplock, and pinfire. Only antique firearm enthusiasts are now concerned with them. Modern shooters must only know about rimfire and centerfire primers.

Rimfire Primers

The rimfire primer encircles the base of the cartridge’s shell casing. The clever thing about its design is that it lets the firing pin strike anywhere around the casing’s rim to trigger ignition. Because the casing’s brass must be thin for this to happen, you have to load rimfire cartridges to low pressure or risk an explosion in the chamber. This is why rimfire primers are only used in smaller calibers including 17 HMR, 22 LR, and 22 WMR. It would be satisfying to say that rimfire primers are exclusive to rifle and pistol cartridges, but as always there is an exception. The 9mm Flobert shotshell uses a rimfire primer. Its low power is accordingly suited for shooting rats indoors. (Rats do not belong indoors, after all.)

Berdan vs Boxer Centerfire Primers

Single or Double Flash Hole Design

boxer primer pocket

Look toward the base of the open casing and you’ll see the single flash hole of a boxer primer pocket.

Boxers and Berdans are both centerfire primers. The Boxer is by far the more popular in America, while the Berdan is commonly found in European-made ammunition such as that by Wolf, Tula, and Silver Bear. The biggest difference between the two is that Boxer primers have one flash hole in the center while Berdan primers have a double flash hole connecting the primer to the gunpowder of a cartridge. In terms of their performance, Berdan and Boxer primers are about the same.

berdan primer on a table

Look to the base of the casing and you’ll see the double flash hole of the Berdan primer.

Ironically, Hiram Berdan’s invention that is used mostly in foreign ammo received his patent in New York in 1866. A few months later, English Colonel Edward Mounier Boxer patented his own.

How They Work

shotgun primer hit by firing pin

If you look closely, you’ll see the primer on the right has a small indentation mark. That’s where the firing pin of a shotgun made contact started the firing process for this round.

Either type of centerfire primer works on the same principle. A small metal cylinder shaped like a watch battery contains a charge of explosive. When the firing pin strikes the primer, it crushes the explosive to ignite it.

Exactly how the firing pin crushes the explosive is one of the two key differences between Berdans and Boxers.

With Berdan primers, the firing pin crushes the explosive against a hard surface, or anvil, that is part of the shell casing. With the Boxer, the anvil is part of the primer itself.

The other difference between Berdan vs Boxer primers is the route their explosions take to the propellant. In a Berdan primed shell casing, two flash holes connect the primer pocket to the propellant. A Boxer primed shell casing has only one hole positioned under the anvil.

Both primer types deliver interchangeable ignition, muzzle velocity, accuracy, and energy.  The greatest difference you could notice between the two are their price tags. Berdans are slightly less expensive, which is why several foreign countries use them for their militaries’ ammunition.

So, Why Does Boxer or Berdan Matter?

The difference between Berdan vs Boxer is more important to the handloader. They know that removing a spent Berdan takes a good deal more work, and that because they can’t replace the anvil, which is integral to the casing and wears with use, ignition in their reloaded cartridge is less assured. Furthermore, a Boxer’s single flash hole makes its installation more straightforward. Its sizing is also better standardized. If you intend to reload ammunition, Boxer is the better way to go, especially since Berdans are so frequently used in steel casings which are themselves harder to reload than brass.

The big takeaway for the novice shooter is that either Boxer primers or a Berdan primers will work just fine.

Your firearm won’t care which one it hits, and you won’t notice a difference until you go down the handloading rabbit hole. And that’s a rewarding rabbit hole to go down one day — it can save you a lot of money and when you’re rich we hope you’ll remember who gave you this free lesson in Berdan vs Boxer primers!