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Snippet from Wikipedia: Full metal jacket bullet

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.

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. 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. However, jacketed bullets had been in use since at least 1882, over a decade prior to the Hague Convention.

“) for the 7.62x39mm rifle and round-nosed for the 7.62x25mm pistol cartridges.]] A full metal jacket (or FMJ) is a bullet consisting of a soft core (usually made of lead) encased in a shell of harder metal, such as gilding metal, cupronickel or less commonly a steel alloy. This shell can extend around all of the bullet (alternatively termed a total metal jacket round) or, more often, just around the front and sides with the rear lead part left exposed. The jacket 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. The appearance of FMJ ammunition is highly distinctive when compared to hollow-point or soft point bullets. Historically, the first successful full metal jacket rifle bullets were invented by Lt. Col. Eduard Rubin of the Swiss Army in 1882.<ref>(Huon,1988)</ref><ref></ref><ref>Holt Bobinson "The model 1911 Schmidt Rubin: the other Switzer". Guns Magazine. 08 Jun, 2010.</ref><ref>The Gun Digest Book of Firearms Assembly/Disassembly: Centerfire Rifles, Volume 4 by J. B. Wood. Published by Krause Publications, 2003. ISBN 978-0-87349-631-5</ref> Full metal jacket bullets were first used as standard ammunition in 1886, for the French Mle 1886 Lebel rifle.


There are some disadvantages to jacketing a bullet.<ref>Cast Bullet vs Full Metal Jacketed</ref> For instance, full metal jacket bullets have different properties, both in behavior inside the barrel of the gun and also in flight. Whereas hollow point and soft-tipped bullets are designed to expand upon impact, full metal jacket bullets are limited in their capacity to expand. This makes the bullet pierce through, in most cases leading to smaller wound size. Hollow point and soft tipped bullets are for use against soft targets only, such as animals or people, whereas, full metal jacketed bullets can be indiscriminately used against soft and hard targets.

FMJ with variable cores

Some designs of FMJ rifle ammunition inflict more destructive gunshot wounds than others. Not all FMJ bullets contain a simple lead filling. Here are some examples:

Although British Mark 7 .303 ammunition is compliant with the terms of the Hague Convention, it creates more destructive gunshot wounds than standard spitzer bullets due to its internal design. The center of gravity of the Mark 7 bullet is deliberately shifted towards the rear. This is achieved by constructing the front third of the interior of the bullet from a lighter material such as aluminum or wood pulp. The result is a tail-heavy FMJ bullet which yaws violently after hitting the target. The .303 British Mark 7 ammunition has been replaced by the 7.62x51mm NATO. Most 5.45x39mm FMJ ammunition is made with an air space in the tip of the round similarly shifting the weight to the rear causing immediate and violent tumbling when it contacts a soft target. 5.56×45 ammunition traveling at the proper velocity will also tumble and the round will break apart at the cannelure and fragment.

Images of FMJ ammunition

<gallery> Image:25_ACP_-_FMJ_-_SB_-_2.jpg|.25 ACP Image:7.65x17_mm_Browning_ReconTanto.jpg|.32 ACP Image:7.62x25_-_FMJ_-_SB_-_5.jpg|7.62×25mm Tokarev Image:Tokarev,parabellum,32.JPG|.32 ACP, 7.62×25mm Tokarev, 9×19mm Parabellum Image:T_73.JPG|7.65×22mm Parabellum Image:380RevolverMkIIz_Cartridges.JPG|.38 S&W Image:9mm_short.jpg|.380 ACP Image:9mmMakarov.jpg|9×18mm Makarov Image:.38_Super.jpg|.38 Super Image:40_S%26W_-_FMJ_-_4.jpg|.40 S&W Image:45_ACP_-_FMJ_-_SB_-_2.jpg|.45 ACP Image:Yugo_7.62x39_M67.jpg|7.62×39mm Image:7.62x39_-_FMJ_-_2.jpg|7.62×39mm Image:7.62x39_-_FMJ_-_1.jpg|7.62×39mm Image:5.56_x_45_mm_NATO.jpg|5.56×45mm NATO Image:.303ammunition.jpeg|.303 British Image:303vs280RossSB2007.JPG|.280 Ross & .303 British Image:WWI_rifle_ammunition.JPG|7.92×57mm Mauser from World War I Image:World_War_2_German_ammunition.JPG|Steel-cased German 7.92x57mm Mauser manufactured in 1941 Image:8mm_Mauser_stripper_clip%2C_1941_Turkish_military_production.JPG|7.92×57mm Mauser dated 1941 Image:German_7.92x33mm_Kurz.jpg|7.92×33mm Kurz Image:GP11.jpg|7.5×55mm Swiss Image:7,62mm_G3_oder_MG3.jpg|Three recovered 7.62×51mm NATO FMJ bullets (next to an unfired cartridge), showing rifling marks Image:7,62x54mmR Mosin Nagant.jpg|7.62x54mm Image:Soviet-WW2-era-cartridges.jpg|From left to right: 7.62x54mm, 7.62×39mm and 7.62×25mm </gallery>

See also


full_metal_jacket_bullet.txt · Last modified: 2020/03/12 18:34 (external edit)