Full metal jacket bullet

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These .30-caliber (7.62 mm) full metal jacket bullets show the typical jacket openings exposing the lead alloy core on the base of the bullet to illustrate a full metal jacket may not completely enclose the core.

A full metal jacket (FMJ) bullet is a small-arms projectile consisting of a soft core (often lead) encased in a shell of harder metal, such as gilding metal, cupronickel, or, less commonly, a steel alloy. A bullet jacket generally allows for higher muzzle velocities than bare lead without depositing significant amounts of metal in the bore, it also prevents damage to bores from steel or armor-piercing core materials. In military nomenclature, it is often labeled ball ammunition.

The bullet was invented in 1882 by Swiss Colonel Eduard Rubin while he was working for the Swiss Federal Ammunition Factory and Research Center, which developed ammunition for the Swiss military.[1][2][3][4] The use of full metal jacketing in military ammunition came about in part because of the need for improved feeding characteristics in small arms that used internal mechanical manipulation of the cartridge in order to chamber rounds as opposed to externally hand-reloading single-shot firearms.[citation needed] The harder metal used in bullet jackets was less prone to deformation than softer exposed lead, which improved feeding, it is sometimes thought that military use of FMJ ammunition was the result of The Hague Convention of 1899, Declaration III, prohibiting the use in international warfare of bullets that easily expand or flatten in the body.[citation needed] However, this did not address the technical details for acceptable ammunition, and jacketed bullets had actually been in use since at least 1882, and were first used as standard ammunition in 1886 for the French Mle 1886 Lebel rifle, over a decade prior to the Hague Convention.[citation needed]

Impact characteristics[edit]

By design, fully jacketed projectiles have less capacity to expand after contact with the target than a hollow-point projectile. While this can be an advantage when engaging in targets behind cover, it can also be a disadvantage as an FMJ bullet may pierce completely through a target, leading to less severe wounding, and possibly failing to disable the target. Furthermore, a projectile that goes completely through a target can cause unintentional damage downrange of the target.

Cartridges with full metal jacket bullets[edit]

In popular culture[edit]

See also[edit]

References[edit]

  1. ^ (Huon,1988)
  2. ^ "Swiss Handguns 1882". 
  3. ^ "FindArticles.com - CBSi". Archived from the original on 2012-07-15. 
  4. ^ Wood, J. B. (Jay Barclay) (2003). The Gun Digest Book of Firearms Assembly/Disassembly: Centerfire Rifles, Volume 4 (2nd ed ed.). Iola, WI: Krause Publications. ISBN 0873496310. OCLC 52359378. 

External links[edit]