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. The headstamp is punched into the base of the cartridge during manufacture. A resource for identifying where the ammunition originated can be found at Cartridge Collectors.

Albania

The government-operated arsenal K.M. Polican marks number "3" at the 6 o'clock position, and the last two digits of the year at 12 o'clock.

Argentina

Military cartridges have the manufacturer's head stamp at 12 o’clock, and can include a two or four digit year. The following list of manufacturer initials is taken verbatim from:

Resellers

There are companies that do not manufacture or assemble cartridges of their own but import or contract them from another manufacturer. La Porteña ("the young lady from the port town") on business addresses is a nickname for Buenos Aires.

Australia

Austria

Bangladesh

A common head stamp is BOF (Bangladesh Ordnance Factory). Sometimes a two-digit year and/or a caliber may be included.

Belgium

Bolivia

Brazil

Burkina Faso

Cartridges made by Industrial Society Burkina Arms and Ammunition (SIBAM) may be marked SIBAM or CV (Cartoucherie Voltaique (CARVOLT)).

Canada

Arsenals

Civilian contractors

Commercial manufacturers

Colombia

INDUMIL Industria Militar [Colombian Military Industry], company owned by the Government of Colombia operate the only authorised manufacturing company that produce weapons and munitions for both the military and civilian markets. Makes 9×19mm NATO [8 gram / 124 grain bullet], 9×19mm Luger [115 grain bullet], 9×19mm Subsonic [158 grain], 9×19mm Factor 132, .223 Remington, 5.56×45mm NATO, .32 Smith&Wesson, .38 Special, and .38 Special Factor 132. They also make several shotgun shells in 12Ga, 16Ga and 20Ga. Pistol & Rifle ammunition uses "IM" as headstamp, the last 2 digits of the year of manufacture and 2 digits for the designation. Revolver and Shotgun shells are stamped as "Indumil" and the calibre.

China

NORINCO (North Industries Corporation) – Beijing, China. Operates several state arsenals that produce weapons and munitions for both the military and civilian markets. Makes the Big Star rimfire and China Sports centerfire ammunition brands. Currently they make 9×18mm Makarov, 9×19mm Parabellum, .45 ACP, .223 Remington [5.56×45mm], 7.62×39mm Soviet, and .308 Winchester [7.62×51mm] ammo. NORINCO 7.62×39mm Soviet ammunition was banned from importation into the United States in February, 1994. This was due to the fact that the military surplus ammunition couldn't pass the "magnet test". Non-compliant semi-armor-piercing and armor-piercing rounds have steel penetrators or steel cores that will be attracted by a magnet. The NORINCO copper-plated steel-jacketed Full Metal Jacket bullets would be attracted by a magnet – making it hard to distinguish between compliant lead-core and non-compliant steel-cored ammunition.

Arsenals

Ammunition headstamp has the arsenal number and the last 2 digits of the year of manufacture. The following are arsenals known to produce civilian lead-core ammunition.

Manufacturers

Counterfeits

The use of counterfeit ammunition is perplexing, since NORINCO already makes ammunition and sells quite a lot of it. Theories abound: it was made for use by Chinese-backed insurgents, it was designed to get in on the surplus ammo market, or it was designed to make users leery of Western-made surplus ammunition and get them to buy new foreign-made ammo.

Czech Republic

Resellers

There are companies that do not manufacture or assemble cartridges of their own but import or contract them from another manufacturer.

Egypt

What appears like "TO" is actually the Arabic letters for Haa ( ح ) and Mim ( م ), the first letters of the words for "Military Factory". It is an Egyptian Military property mark, much like the broadshead arrowhead used by the British Government. The larger versions of the symbol has the numbers ٧٢ ("27") inset in the circle split by the vertical line. The "TO" is found on the base of shotgun shells, which Military Factory 27 makes for the civilian hunting market.

Germany

Resellers

There are companies that do not manufacture or assemble cartridges of their own but import or contract them from another manufacturer.

Greece

Italy

Mexico

Romania

Slovakia

South Africa

Sweden

Turkey

United Kingdom

United States

Manufacturers

Ammunition Manufacturers' Association (Winchester Repeating Arms Company, US Cartridge Company, Union Metallic Cartridge, and Phoenix Metallic Cartridge Company) [1900-1907]. The 'Big Four' formed a group that cut out any arms companies they saw as a potential threat (like Savage and Western). They refused to make ammunition for them or even sell them the components. It fell apart in 1907 due to internal squabbling. The side-effect is that their methods forced their spurned customers to become rivals who made their own components and assembled their own cartridges. Union Metallic Cartridge got bought out by Remington Arms in 1912, US Cartridge Company was bought out by National Lead Company (who owned Winchester) in 1918, followed by Winchester being bought out by Olin Industries (who owned Western Cartridge) in 1931.

Resellers

There are companies that do not manufacture or assemble cartridges of their own but import or contract them from another manufacturer.

Yugoslavia

Military Headstamps

Military cartridge headstamps do not usually have the caliber and cartridge name on it. The headstamp may have a 2- or 3-symbol letter, number, or alphanumeric code indicating the place of manufacture. This is usually followed by two digits indicating the last two digits of the year of manufacture; they may have additional digits or a letter indicating the month or yearly quarter of manufacture. The packaging usually has the manufacturer code, 2-digit year, and a lot number on it so bad or suspect batches can be removed.