Green bullet

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M855A1 projectiles for 5.56x45mm NATO rifles replace traditional lead alloy cores with an environmentally friendly copper core with a 19-grain (1.2 g) steel "stacked-cone" penetrating tip. 5.56 M855A1 Enhanced Performance Round.jpg
M855A1 projectiles for 5.56×45mm NATO rifles replace traditional lead alloy cores with an environmentally friendly copper core with a 19-grain (1.2 g) steel "stacked-cone" penetrating tip.
Solid copper bullets typical of the majority of nonlead ammunition certified for hunting in California. The .25 caliber (6.4 mm) bullet on the left has a small cylindrical cavity in the nose, and the .35 caliber (9 mm) bullet on the right has a larger cavity holding an aerodynamic plastic tip. CopperBullets.png
Solid copper bullets typical of the majority of nonlead ammunition certified for hunting in California. The .25 caliber (6.4 mm) bullet on the left has a small cylindrical cavity in the nose, and the .35 caliber (9 mm) bullet on the right has a larger cavity holding an aerodynamic plastic tip.

Green bullet, green ammunition or green ammo are nicknames for a United States Department of Defense program to eliminate the use of hazardous materials from small arms ammunition and from small arms ammunition manufacturing. Initial objectives were elimination of ozone-depleting substances, volatile organic compounds, and heavy metals from primers and projectiles. These materials were perceived as causing difficulties through the entire life cycle of ammunition. The materials generated hazardous wastes and emissions at manufacturing facilities and use of ammunition caused contamination at shooting ranges. Potential health hazards made demilitarization and disposal of unused ammunition difficult and expensive. [2]

Contents

The Joint Working Group for Non-Toxic Ammunition was formed by the Small Caliber Ammunition Branch of the United States Army Armament Research, Development and Engineering Center in October 1995. Members of the working group included the National Guard of the United States, the United States Coast Guard, the United States Army Infantry School, the Industrial Operations Command, the Lake City Army Ammunition Plant, the Oak Ridge National Laboratory, the Los Alamos National Laboratory and the United States Department of Energy Kansas City Plant. [2]

Background

In 2013, lead bullet production represented the second largest use of lead in the U.S., after lead-acid batteries. [3] Studies by the U.S. CDC suggest blood lead levels are correlated with self-reported consumption of game meat. [4]

Legislation

October 11, 2013 Governor Jerry Brown of California signed into law AB 711 Hunting: nonlead ammunition. [5] Cost reductions from conversion to green ammo are estimated at "$2.5 million required for waste removal at each outdoor firing range as well as the $100 thousand annual costs for lead contamination monitoring". [6]

Identified hazardous materials

Hazardous materialLocation [2] New material
antimony projectile tungsten-tin or -nylon [7]
antimony trisulfide primer diazodinitrophenol (DDNP) [8]
barium nitrate tracer or incendiary projectile
barium peroxide primer and tracer or incendiary projectilediazodinitrophenol
ethyl acetate blank cartridge tip sealantSolventless process [9]
ethyl alcohol tracer or incendiary projectile
glycol ether painted projectile point
lead projectilesteel [10] tungsten-tin or tungsten-nylon [11] [12] [13] copper [14]
lead dioxide tracer or incendiary projectile
lead styphnate primerdiazodinitrophenol, MIC, e.g. Al/MoO3
methyl chloroform casemouth sealant and tracer or incendiary projectile
methyl ethyl ketone primer and sealants for primer pocket and blank cartridge tipSolventless process
methyl isopropyl ketone primer and sealants for primer pocket and blank cartridge tipSolventless process
toluene primer and sealants for primer pocket and blank cartridge tipSolventless process
xylene sealants for primer pocket and blank cartridge tip

Green ammunition

Jim Newill explains the effectiveness of the Army's 5.56mm M855A1 Enhanced Performance Round (2011) US Army green bullet test.jpg
Jim Newill explains the effectiveness of the Army's 5.56mm M855A1 Enhanced Performance Round (2011)

Two green ammunition cartridges are the 5.56×45mm NATO M855A1 and the MK281 40 mm grenade. Switching to the 5.56 mm green bullet, the M855A1 Enhanced Performance Round, or EPR, in 2010 has eliminated nearly 2,000 tons of lead from the waste stream. [15] U.S. Army representatives at a 2013 House Armed Services Committee hearing have credited the 5.56mm M855A1 Enhanced Performance Round “close to” those of a 7.62mm in its performance capabilities. [16] The longer, less dense M855A1 bullet must be seated deeper than the lead core bullet it replaced to maintain the same exterior cartridge dimensions required for reliable functioning in self-loading firearms; and higher pressure is required to obtain the same bullet velocity with reduced propellant volume. Increased pressure causes gas port erosion producing a higher cyclic rate of automatic fire making jamming malfunctions more likely. Cracks in bolt locking lugs have been observed after 3000 rounds of full automatic fire with the M855A1 cartridge. [17]

Enhanced Performance Round, Lead-Free

The Army Research Laboratory and other participants developed the M855A1, Enhanced Performance Round (EPR), by applying ballistics concepts originally used in large-caliber cartridges to small arms. The result was significant improvements to lethality of small arms. [18] [19] The 5.56-mm (M855A1) ammunition was first battle-tested in mid-2010 in Afghanistan. The 7.62-mm (M80A1) ammunition was fielded in 2014. [18]

The EPR “bronze tip” ammo – previously known generically as “Green Ammo” – was born at the kickoff meeting for Phase II of the Army's Green Ammunition replacement program in mid-2005, at the Lake City Army Ammunition Plant. Participants met to discuss problems surrounding environmentally-friendly small arms training ammunition. [18]

The program team was composed of Project Manager, Maneuver Ammunition Systems (PM-MAS), Army Research Laboratory (ARL), U.S. Army Armaments Research Development and Engineering Center (ARDEC), and other team members. Participants evaluated more than 20 potential projectile designs before moving forward with a three-piece, reverse-jacket bullet design incorporating a hardened steel penetrator and lead-free slug. [20]

The EPR produces consistent effects against soft targets; increased effectiveness at long ranges; increased defeat of hard targets; and reduced muzzle flash (to help conceal soldiers’ firing positions). The lead-free cartridges also reduce environmental impact by removing more than 2,000 metric tons of lead per year that otherwise could end up in the environment. [18] [19]

The EPR contains an environmentally-friendly projectile that eliminates lead from the manufacturing process in direct support of Army commitment to environmental stewardship. [21] Under the Green Ammo Phase II initiative, the Army focused on lead-free ammo in stateside training ranges, in response to tightening state environmental regulations. [18]

Wildfire considerations

Some of a bullet's kinetic energy is typically converted to heat if the bullet strikes a hard surface like rock. Collision debris may include high temperature bullet fragments as sparks. Steel core and solid copper ammunition have the highest potential to start wildfires. Lead core bullets are less likely to ignite surrounding vegetation. [22] [23]

Rifling considerations

Rifling is required to stabilize elongated bullets, and longer bullets require faster rotation for similar stability. The rate of rotation is determined by the twist of the lands and grooves engraved on the interior of a rifled barrel. Twist is usually expressed as the length of barrel (in inches) in which the bullet will rotate through a full 360 degrees; so bullets fired from a 1:10" twist rifle will make a complete rotation in every 10 inches (25 cm) of distance traveled. [24]

Since lead is a very dense material, bullets made of inexpensive, non-toxic materials will be lighter than bullets made of lead unless bullet length is increased. Inferior external ballistics cause lighter bullets to be less effective against distant targets. Increasing bullet length may require a faster rifling twist to maintain stability. Some early trials versions of the M16 rifle had 1:14" twist barrels, but this was increased to 1:12" twist in early military production to improve stability with 55-grain (3.6 g) M193 lead-core bullets in the early 5.56×45mm NATO cartridges. Twist was increased to 1:9" after combat experience demonstrated the advantages of longer 62-grain (4.0 g) M855 bullets with a portion of the lead core replaced by a less dense steel penetrator. Barrels with 1:7" twist have been used in 21st century 5.56×45mm NATO firearms and have replaced barrels of older United States military firearms to stabilize longer M856 tracer bullets and M855A1 green bullets of less dense materials. [25]

See also

Related Research Articles

<span class="mw-page-title-main">5.56×45mm NATO</span> Service rifle cartridge

The 5.56×45mm NATO is a rimless bottlenecked intermediate cartridge family developed in the late 1970s in Belgium by FN Herstal. It consists of the SS109, L110, and SS111 cartridges. On 28 October 1980, under STANAG 4172, it was standardized as the second standard service rifle cartridge for NATO forces as well as many non-NATO countries. Though they are not entirely identical, the 5.56×45mm NATO cartridge family was derived from and is dimensionally similar to the .223 Remington cartridge designed by Remington Arms in the early 1960s.

<span class="mw-page-title-main">Bullet</span> Projectile propelled by a firearm, sling, or air gun

A bullet is a kinetic projectile, a component of firearm ammunition that is shot from a gun barrel. They are made of a variety of materials, such as copper, lead, steel, polymer, rubber and even wax; and are made in various shapes and constructions, including specialized functions such as hunting, target shooting, training, and combat. Bullets are often tapered, making them more aerodynamic. Bullet size is expressed by weight and diameter in both imperial and metric measurement systems. Bullets do not normally contain explosives but strike or damage the intended target by transferring kinetic energy upon impact and penetration.

<span class="mw-page-title-main">Cartridge (firearms)</span> Pre-assembled firearm ammunition consisting of a casing, projectile, propellant, and primer

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.

<span class="mw-page-title-main">.40 S&W</span> Pistol cartridge

The .40 S&W (10.2x21mm) is a rimless pistol cartridge developed jointly by American firearms manufacturers Smith & Wesson and Winchester in 1990. The .40 S&W was developed as a law enforcement cartridge designed to duplicate performance of the Federal Bureau of Investigation's (FBI) reduced-velocity 10mm Auto cartridge which could be retrofitted into medium-frame semi-automatic handguns. It uses 0.40-inch (10 mm) diameter bullets ranging in weight from 105 to 200 grains.

<span class="mw-page-title-main">9×19mm Parabellum</span> Pistol cartridge designed by Georg Luger

The 9×19mm Parabellum is a rimless, tapered firearms cartridge.

<span class="mw-page-title-main">.22 Long Rifle</span> Common ammunition cartridge

The .22 Long Rifle, also known as the .22 LR or 5.6×15mmR, is a long-established variety of .22 caliber rimfire ammunition originating from the United States. It is used in a wide range of firearms including rifles, pistols, revolvers, and submachine guns.

<span class="mw-page-title-main">.223 Remington</span> Firearms cartridge

The .223 Remington is a rimless, bottlenecked, centerfire rifle cartridge. It was developed in 1957 by Remington Arms and Fairchild Industries for the U.S. Continental Army Command of the United States Army as part of a project to create a small-caliber, high-velocity firearm. The .223 Remington is considered one of the most popular common-use cartridges and is currently used by a wide range of semi-automatic and manual-action rifles.

The .30-06 Springfield cartridge, 7.62×63mm in metric notation, and called the .30 Gov't '06 by Winchester, was introduced to the United States Army in 1906 and later standardized; it remained in military use until the late 1970s. In the cartridge's name, ".30" refers to the nominal caliber of the bullet in inches; "06" refers to the year the cartridge was adopted, 1906. It replaced the .30-03 Springfield, 6mm Lee Navy, and .30-40 Krag cartridges. The .30-06 remained the U.S. Army's primary rifle and machine gun cartridge for nearly 50 years before being replaced by the 7.62×51mm NATO and 5.56×45mm NATO, both of which remain in current U.S. and NATO service. The cartridge remains a very popular sporting round, with ammunition produced by all major manufacturers.

<span class="mw-page-title-main">.243 Winchester</span> Rifle cartridge

The .243 Winchester (6×52mm) is a popular sporting rifle cartridge. Developed as a versatile short action cartridge to hunt both medium game and small game alike, it "took whitetail hunting by storm" when introduced in 1955, and remains one of the most popular whitetail deer cartridges. It is also commonly used for harvesting blacktail deer, pronghorns and mule deer with heavier rounds, and is equally suited to varmint hunting with lighter rounds. The .243 is based on a necked down .308 Winchester, introduced only three years earlier. Expanding monolithic copper bullets of approximately 80 to 85 grains or traditional lead rounds of 90 to 105 grains with controlled expansion designs are best suited for hunting medium game, while lighter rounds are intended for varmints.

<span class="mw-page-title-main">6.8mm Remington SPC</span> Intermediate rifle cartridge

The 6.8mm Remington Special Purpose Cartridge is a rimless bottlenecked intermediate rifle cartridge that was developed by Remington Arms in collaboration with members of the U.S. Army Marksmanship Unit and United States Special Operations Command to possibly replace the 5.56 NATO cartridge in short barreled rifles (SBR) and carbines. Based on the .30 Remington cartridge, it is midway between the 5.56×45mm NATO and 7.62×51mm NATO in bore diameter. It uses the same diameter bullet as the .270 Winchester hunting cartridge.

<span class="mw-page-title-main">Armor-piercing bullet</span> Type of ammunition

Armor-piercing bullets for rifle and handgun cartridges are designed to penetrate ballistic armor and protective shields intended to stop or deflect conventional bullets. Although bullet design is an important factor with regard to armor penetration, the ability of any given projectile to penetrate ballistic armor increases with increasing velocity. Rifle cartridges typically discharge bullets at higher muzzle velocity than handgun cartridges due to larger propellant charge. However, even the same cartridge fired from a rifle will, in almost all common cases, have a higher velocity than when fired from a handgun. This is due to the longer period of acceleration available within the longer gun barrel of rifles, which allow adequate time for the propellant to fully ignite before the projectile exits the barrel. For this reason, bullets fired from rifles may be more capable of piercing armor than similar or identical bullets fired from handguns. In addition, a small-caliber bullet has higher sectional density than a larger-caliber bullet of the same weight, and thus is more capable of defeating body armor.

<span class="mw-page-title-main">Comparison of the AK-47 and M16</span> Comparison of two notorious assault rifles

The two most common assault rifles in the world are the Soviet AK-47 and the American M16. These Cold War-era rifles have been used in conflicts both large and small since the 1960s. They are used by military, police, security forces, revolutionaries, terrorists, criminals and civilians alike and will most likely continue to be used for decades to come. As a result, they have been the subject of countless comparisons and endless debate.

<span class="mw-page-title-main">6.5mm Grendel</span> Rifle cartridge

The 6.5mm Grendel is an intermediate cartridge jointly designed by British-American armorer Bill Alexander, competitive shooter Arne Brennan and Lapua ballistician Janne Pohjoispää, as a low-recoil, high-precision rifle cartridge specifically for the AR-15 platform at medium/long range. It is an improved variation of the 6.5mm PPC.

The 5.8×42mm / DBP87 is a military bottlenecked intermediate cartridge developed in the People's Republic of China. There is limited information on this cartridge, although the People's Liberation Army claims that it is superior to the 5.56×45mm NATO and Soviet 5.45×39mm cartridges.

The 7.5×54mm French, 7.5 French, or 7.5 MAS is a rimless bottlenecked rifle cartridge. It was developed by France as an update to the 7.5×57mm MAS mod. 1924 cartridge. It replaced the obsolete 8×50mmR Lebel round used during World War I, and served as the French service cartridge until superseded by the 5.56×45mm NATO and 7.62×51mm NATO cartridges in the 1970s and 1980s.

The following are terms related to firearms and ammunition topics.

<span class="mw-page-title-main">7.62×51mm NATO</span> Rimless, centerfire, bottlenecked rifle cartridge

The 7.62×51mm NATO is a rimless, bottlenecked rifle cartridge. It is a standard for small arms among NATO countries.

<span class="mw-page-title-main">FN 5.7×28mm</span> Handgun cartridge manufactured by FN Herstal

The FN 5.7×28mm is a small-caliber, high-velocity, smokeless-powder, rebated, bottleneck, centerfire cartridge designed for pistols and personal defense weapons (PDW) uses, manufactured by FN Herstal. It is similar in length to the .22 WMR and .22 Hornet. Unlike many new cartridges, it has no parent case; the complete package was developed from scratch by FN.

The .277 Wolverine (6.8x39mm) is a wildcat cartridge. It is a multi-purpose mid-power cartridge with increased ballistic performance over the AR-15's traditional .223 Remington cartridge. The use of a modified 5.56 case means that at minimum, only a new barrel is needed to convert any 5.56-based firearm to .277 Wolverine.

The .277 Fury or 6.8×51mm Common Cartridge, is a centerfire rimless bottlenecked rifle cartridge announced by SIG Sauer in late 2019. Its hybrid three-piece cartridge case has a steel case head and brass body connected by an aluminum locking washer to support the high chamber pressure of 80,000 psi (551.6 MPa).

References

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  8. Michael Courtney and Amy Courtney (2012). "High-speed measurement of firearm primer blast waves". arXiv: 1203.2701 [physics.pop-ph].
  9. T. G. Manning; D. Thompson; M. Ellis; R. Lieb; M. Leadore; J. Colburn; B. E. Homan; D. A. Worrell; K. B. Moran; S. J. Ritchie. "Environmentally Friendly 'Green' Propellant for the Medium Caliber Training Rounds". Archived from the original on 2010-01-10. Retrieved 2013-12-23.
  10. Information Search of Toxic-Free Ammunition, DTIC A336762, 1994, http://www.dtic.mil/dtic/tr/fulltext/u2/a336762.pdf Archived 2017-02-26 at the Wayback Machine
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  12. 1994 report: Tungsten ‘highly toxic', 2007, updated 2011 http://www.capecodtimes.com/article/20070222/NEWS01/302229999
  13. Army to scrap tungsten bullets, 2008 http://www.capecodtimes.com/article/20080911/NEWS/809110313
  14. National Guard goes green with copper bullets, 2012 http://www.capecodtimes.com/article/20120926/NEWS/209260326
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  19. 1 2 "U.S. Army Begins Shipping M855A1 Enhanced Performance Round (M855A1 EPR) a.k.a. "Green Ammo" Improved 5.56mm NATO Round to Warfighters: Green Tip M855 Ball Ammo Gets a Serious Upgrade". DefenseReview.com. Archived from the original on July 2, 2010. Retrieved 2018-07-25.
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