page_title: Cartridge (firearms)
section_title: Bullet design types
hierarchical_section_title: Cartridge (firearms) / Bullet design types
caption_attribution_description: A cutaway showing a Japanese Navy 7.7 mm rimed rounds as fired by the Type 92 and Type 97 machine guns - copies of Vickers and Lewis designs. The round is effectively interchangeable with British .303
context_page_description: A cartridge or a round is a type of pre-assembled firearm ammunition packaging a projectile, a propellant substance and an ignition device within a metallic, paper or plastic case that is precisely made to fit within the barrel chamber of a breechloading gun, for the practical purpose of convenient transportation and handling during shooting. Although in popular usage the term "bullet" is often used to refer to a complete cartridge, it is correctly used only to refer to the projectile.
  Cartridges can be categorized by the type of their primers — a small charge of an impact- or electric-sensitive chemical mixture that is located either at the center of the case head, inside the rim of the case base, inside the walls on the fold of the case base that is shaped like a cup, in a sideways projection that is shaped like a pin, or a lip, or in a small nipple-like bulge at the case base.
  Military and commercial producers continue to pursue the goal of caseless ammunition. Some artillery ammunition uses the same cartridge concept as found in small arms. In other cases, the artillery shell is separate from the propellant charge.
  A cartridge without a projectile is called a blank.
context_section_description: A shotgun shell loaded with multiple metallic "shot", which are small, generally spherical projectiles.
  Shotgun slug: A single solid projectile designed to be fired from a shotgun.
  Baton round: a generally non-lethal projectile fired from a riot gun.
  Armor Piercing (AP): A hard bullet made from steel or tungsten alloys in a pointed shape typically covered by a thin layer of lead and or a copper or brass jacket. The lead and jacket are intended to prevent barrel wear from the hard core materials. AP bullets are sometimes less effective on unarmored targets than FMJ bullets are. This has to do with the reduced tendency of AP projectiles to yaw (turn sideways after impact).
  Flat Nose Lead (FNL): Similar to the above, with a flattened nose. Common in Cowboy Action Shooting and plinking ammunition loads.
  Full Metal Jacket (FMJ): Made with a lead core surrounded by a full covering of brass, copper, or mild steel. These usually offer very little deformation or terminal performance expansion, but will occasionally yaw (turn sideways). Despite the name, a FMJ bullet typically has an exposed lead base, which is not visible in an intact cartridge.
  Glaser Safety Slug: copper jackets filled with bird shot and covered by a crimped polymer endcap. Upon impact with flesh, the projectile is supposed to fragment, with the birdshot spreading like a miniature shotgun pattern.
  Jacketed Hollow Point (JHP): Soon after the invention of the JSP, Woolwich Arsenal in Great Britain experimented with this design even further by forming a hole or cavity in the nose of the bullet while keeping most of the exterior profile intact. These bullets could theoretically deform even faster and expand to a larger diameter than the JSP. In personal defense use, concerns have arisen over whether clothing, especially heavy materials like denim, can clog the cavity of JHP bullets and cause expansion failures.
  Jacketed Soft Point (JSP): In the late 19th century, the Indian Army at Dum-Dum Arsenal, near Kolkata, developed a variation of the FMJ design where the jacket did not cover the nose of the bullet. The soft lead nose was found to expand in flesh while the remaining jacket still prevented lead fouling in the barrel. The JSP roughly splits the difference between FMJ and JHP. It gives more penetration than JHP but has better terminal ballistic characteristics than the FMJ.
  Round Nose Lead (RNL): An unjacketed lead bullet. Although largely supplanted by jacketed ammunition, this is still common for older revolver cartridges. Some hunters prefer roundnose ammunition for hunting in brush because they erroneously believe that such a bullet deflects less than sharp-nosed spitzer bullets, regardless of the fact that this belief has been repeatedly proven not to be true. Refer to American Rifleman magazine.
  Total Metal Jacket (TMJ): Featured in some Speer cartridges, the TMJ bullet has a lead core completely and seamlessly enclosed in brass, copper or other jacket metal, including the base. According to Speer literature, this prevents hot propellant gases from vaporizing lead from the base of the bullet, reducing lead emissions. Sellier & Bellot produce a similar version that they call TFMJ, with a separate end cap of jacket material.
  Wadcutter (WC): Similar to the FNL, but completely cylindrical, in some instances with a slight concavity in the nose. This bullet derives its name from its popularity for target shooting, because the form factor cuts neat holes in paper targets, making scoring easier and more accurate and because it typically cuts a larger hole than a round nose bullet, a hit centered at the same spot can touch the next smaller ring and therefore score higher.
  Semi Wad Cutter (SWC) identical to the WC with a smaller diameter flap pointed conical or radiused nose added. Has the same advantages for target shooters but is easier to load into the gun and works more reliably in semi-automatic guns. This design is also superior for some hunting applications.
  Truncated Cone, Round Nose Flat Point, etc. Descriptive of typical modern commercial cast bullet design
caption: A cutaway showing a Japanese Navy 7.7 mm rimmed rounds as fired by the Type 92 and Type 97 machine guns—copies of Vickers and Lewis designs. The round is effectively interchangeable with .303 British.
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