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 left cartridge's headstamp says "FC 223 REM" which means that it was made by Federal Cartridge Co. and it is in the caliber ".223 Remington". The cartridge on the right has a headstamp that says "LC 99" with a symbol that consists of a cross in a circle. This cartridge was made in 1999 by the Lake City Army Ammunition Plant, in Independence, Missouri, USA. The symbol on this headstamp means it meets NATO specifications.
Cartridge base with a headstamp by Hirtenberger
RWS headstamp on an 8×68mm S rifle cartridge
A cartridge, also known as a round, is a type of pre-assembled firearm ammunition packaging a projectile, a propellant substance and an ignition device (primer) within a metallic, paper, or plastic case that is precisely made to fit within the barrel chamber of a breechloading gun, for convenient transportation and handling during shooting. Although in popular usage the term "bullet" is often used to refer to a complete cartridge, the correct usage only refers to the projectile.
A variety of rifle cartridges: (1).17 HM2 (2).17 HMR (3).22LR (4).22 Win Mag R/F.22 WMR (5).17/23 SMc (6)5mm/35 SMc (7).22 Hornet (8).223 Remington (9).223 WSSM (10).243 Win (11).243 Win Improved (Ackley) (12).25-06 Remington (13).270 Winchester (14).308 Winchester (15).30-06 Springfield (16).45-70 Government (17).50-90 Sharps
Three non-bottlenecked cartridges (9×19mm Parabellum, .40 S&W and .45 ACP) on the left, three bottlenecked cartridges (FN 5.7×28mm, 5.56×45mm NATO and .300 Winchester Magnum) in the center, and two polymer-cased 12-gauge shotshells on the right
Smokeless powders used for handloading
Percussion caps, the precursor of modern primers
