Did you ever wonder what makes ammunition,’ bullets’ go bang? Well it’s a pretty simple process, that is activated by the weapons firing pin! Modern cartridge type ammunition, has a small ‘cap’ ,called the primer, that is inserted into the pocket, or base of the cartridge. There are two types of primers used in ammunition. One is the Berdan, and the other is a Boxer,
Both of these primers were developed in the 1860’s , Hiram Berdan, the namesake of the Berdan patented the Berdan primer in 1866. He was an engineer and inventor, and had many inventions under his belt, he was a renowned marksman, and a US Brig Gen. over the volunteer sharpshooters during different phases of the Civil War. Col. Edward M. Boxer, Superintendent of the Royal Arsenal, England developed the ‘Boxer’ primer and was patented in the U.S. in 1869. He also had many ammunition inventions to his credit, the Boxer Rocket, that was used for many years. While these guys were credited in the books as the inventors, there were other people involved with the process of these primers.
The picture above is Hiram Berdan. I was unable to locate a picture of Boxer.
Now, what primer does the ammo have, that I buy today? Well f you are the in US, you have the Boxer primer. Now if you buy old surplus military ammo such as the British .303 it has Berdan primers. Most all your modern ammo today has boxer primers, even from overseas companies.
Now why do we use the ‘British’ boxer primer? Well it boils down to politics and capitalism.
Let me digress.. The British government have always had strict gun control policies in place, and only the privileged had the means to obtain, and the Berdan primed ammo was relatively cheap to produce, and pretty much could not be re-loaded. Where as the US everyone had weapons, and being under populated and people living away from areas of industry, they wanted ammunition they could reload, while a cost more upfront, they saved in the long run, because the reloading was cheaper.
Here are a couple of illustrations and pictures of the two types of primers. The Berdan is the one on the right. The Berdan primer is basically a cup with a compound that ignites when crushed against the Berdan shells anvil, which looks like a bump in the primer pocket between the two flash holes, and the boxer primer is a cup with compound and anvil built into the primer
Ok, ok I hear you! What’s rim fire? Rim fire is a type of low pressure cartridge, for example .22long rifle cartridge. The rim of the rimfire cartridge is essentially an extended and widened percussion cap which contains the priming compound. The firing pin strikes the rim of the cartridge base. These type of cartridge cannot be reloaded
These pictures show where the firing pin hits the rim as compared to centerfire
After the primer is struck it ignites the powder charge in cartridge, thus creating the pressure to send the projectile down range. The powders used for cartidges and shotgun shells are smokeless type, and varies on the shape, density, and burn rate. They are measured in drams and grains. And there are so many brands and types, it can make you dizzy just trying to figure out what you need to reload! Never go over the amount specified by the reloading manuals.
The cartidges we use today are made of brass, mild steel, nickel , or aluminum, with the brass being most durable for reloading. Now some companies are making polymer or plastic casings for military to reduce weight of ammo.
Now who invented the metal cartridge? It was invented by Frenchman Casimir Lefaucheux in 1828 but not patented until 1835. This bullet was one of the earliest designs of a metallic cartridge , and closely associated with the invention of the breech loader.
Wow, this is definitely head spinning as to the different types of ammo available!
I have been reloading ammunition for many years, and definitely understand why the prices have went through the roof, especially with metal prices higher than they have ever been, including copper. The gear needed to reload is quite expensive itself. But it is fun and rewarding to learn the process, and to go out and shoot your own ammo! This last photo shows ammunition size compared to a dollar bill and a double A battery. I hope this little article helps you understand how ammunition works