A Guide To Choose The Best Primers For Your Cartridge

Many would think of guns and ammunition when it comes to shooting supplies. But, in reality, there are many more things that are considered shooting supplies. Reloading tools, brass, powder, primers and bullets are essential shooting supplies. There are different shooting supplies if you are practising in an indoor range. Indoor shooters need shooting muffs for the ears, standardising marksmanship targets and gloves for hands. Overall, shotgun sports have their shooting supplies which are different from hunters.

Despite the shooting range, primers are a critical part of shooting. Modern 209 Primers or other primers we are using today result from centuries of development. The journey of igniting the gunpowder that had started with glowing matches went through the flintlock and percussion caps and now arrived at the primers.

Pinfire Primers

In 1828,  Casimir Lefaucheaux made the first pinfire primer in which he used a fulminate of mercury as an igniting compound. Mercury’s fulminate is explosive and sensitive, and therefore, it can catch fire or blast with a little friction, heat or shock. Moreover, it is prone to water contamination and generates a substantial amount of leftovers. If these leftovers are not cleaned quickly from the firearm, they might cause rusting throughout the weapon. Storing mercuric primers for a longer time initiates decomposition that leads to misfire or hang-fires.

Modern Primers

If you ask shooters the primary role of a primer, they would tell you that it is like a match that ignites the gunpowder and starts ejecting bullets from the firearm with a rapid force. This explanation is incorrect, and we need to go through the chemistry to know what a primer exactly does.

The primer contains a primer compound, which is sensitive and dangerous. When a shooter presses the trigger, the primer compound is pressed between the primer’s cup and anvil. You can not be cosy with primer compound as if you have not handled it properly; it has the capacity to create a crater full of smoke.

Another way to understand how a primer works is to consider a tiny volcano or rocket engine that splits an explosive yet hot compound that combines with the cartridge’s gunpowder. This compound was developed in 1920 by mixing lead styphnate with barium nitrate. The lead styphnate is explosive, and barium nitrate is an oxidiser that adds oxygen to the flame. These two elements take 80 per cent of the primer compound and the rest 20 per cent is some fuels and sensitisers.

Type Of Primers

Two types of primers come in two sizes. Primers used in pistols have softer and thinner primer cups in comparison to primers used in rifles. A cup of .175’’ diameter is used in small primers, while large primers utilise cups of 0.210’’. Rifle primers are somewhat thicker than pistol primers. Small rifle primers are considered ideal for a high-performance modern handgun cartridge due to their strongness and thickness.

The two basic types of primers are Boxer and Berdan. Broadly, the bullets manufactured in the United States utilise Boxer primers. These primer cups contain a small amount of explosive compound in the base. When the trigger is pressed, the pin hits the cup’s base, which ignites the primer compound. On the other hand, Berdan primers depend on an anvil that comes in-built in the primer’s cup area.

How To Choose Primers For Cartridge?

When choosing primers for ammo, don’t rely too much on big names. For example, if you assume that .38 special bullets have .38 calibre, you are wrong. While purchasing primers, you must not make assumptions while purchasing primers because if you believe that large rifle primers are for a large rifle cartridge, you might be wrong. Therefore, it is recommended to visit a reliable shooting supplies store to purchase primers. They will tell you which primers will be ideal for your cartridge in terms of performance.

Pro Tips For Handling Primers

  • If you are coming across issues with your priming tools, whether it is a modern reloading tool or hand device, choose a different brand of primers.
  • Always try to keep primers in their case as they are sensitive and explosive; a slight mistake can turn things badly.
  • Choose primers by the diameter of their cups, not based on primer compound or brand.
  • Avoid using primers that contain decomposable substances because if they get slight moisture, they will lead to misfire or hang-fire


No doubt, primers are essential shooting supplies, and an experienced shooter or hunter will never compromise with them. We have compiled all the information with the intention to help readers can make an informed decision while purchasing primers for their ammo and hope this write-up will guide you in making the aptest choice.

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