What do the markings on the bottom of a bullet mean?

headstamp
A headstamp is the markings on the bottom of a cartridge case designed for a firearm. It usually tells who manufactured the case. If it is a civilian case it often also tells the caliber: if it is military, the year of manufacture is often added.

What is a primer bullet?

In firearms and artillery, the primer (/ˈpraɪmər/) is the chemical and/or device responsible for initiating the propellant combustion that will push the projectiles out of the gun barrel. In smaller weapons the primer is usually of the first type and integrated into the base of a cartridge.

What other types of markings can be found on bullets and casings?

Firing pin impressions, extractor marks, ejector marks, and chamber marks, when present and of sufficient in quality, are all features used by firearms examiners in their analysis.

What are the individual markings on a bullet?

A barrel will produce individual markings in addition to a bullet’s land and groove impressions as the bullet passes through, and it is these unique markings that an examiner evaluates to determine whether a given bullet was fired from a particular firearm.

What is inside primer of bullet?

Primers are made of a copper or brass alloy cup with a brass anvil and are filled with an impact-sensitive lead styphnate igniter. The metal parts of the primer are usually nickel-plated to resist corrosion. Propellants can vary from black gunpowder to a more modern smokeless powder which contains nitrocellulose.

Where is the breech face mark located?

Breech face marks- These marks come from the area surrounding the firing pin of the firearm. After the cartridge powder is ignited by the firing pin striking the primer cup, tremendous pressure is exerted in the chamber of the firearm, forcing the back of the cartridge case against the breech face of the firearm.