5.56x45mm NATO
Encyclopedia
5.56×45mm NATO is a rifle
cartridge
developed in the United States
and originally chambered in the M16 rifle
. Under STANAG
4172, it is a standard cartridge for NATO forces as well as many non-NATO countries. It is derived from, but not identical to, the .223 Remington
cartridge. When the bullet impacts at high velocity and yaw
s in tissue, fragmentation creates a rapid transfer of energy which can result in dramatic wounding effects.
, derived from the .308 Winchester
rifle cartridge and designed to replace the U.S. military's .30-06 Springfield
rifle cartridge. At the time of selection, there had been criticism that the 7.62 mm was too powerful for modern service rifle
s, causing excessive recoil, and that the weight of the ammunition did not allow for enough rate of fire
in modern combat.
The British had extensive evidence with their own experiments into an intermediate cartridge since 1945 and were on the point of introducing a .280 inch (7 mm) cartridge
when the selection of the 7.62 mm NATO was made. The FN
company had also been involved. The concerns about recoil and effectiveness were effectively overruled by the US within NATO, and the other NATO nations accepted that standardization was more important at the time than selection of the ideal cartridge. However the concerns would prove to be valid and led to the development of the 5.56 cartridge.
During the late 1950s, ArmaLite
and other U.S. firearm
designers started their individual Small Caliber/High Velocity (SCHV) assault rifle experiments using the commercial .222 Remington
cartridge. When it became clear that there was not enough powder capacity to meet U.S. Continental Army Command's (CONARC) velocity and penetration requirements, ArmaLite contacted Remington to create a similar cartridge with a longer case body and shorter neck. This became the .222 Remington Special. At the same time, Springfield Armory
's Earle Harvey had Remington create an even longer cartridge case then known as the .224 Springfield. Springfield was forced to drop out of the CONARC competition, and thus the .224 Springfield was later released as a commercial sporting cartridge known as the .222 Remington Magnum
. To prevent confusion with all of the competing .222 cartridge designations, the .222 Remington Special was renamed the .223 Remington
. After playing with their own proprietary cartridge case design, the .224E1 Winchester, Winchester eventually standardized their case dimensions, but not overall loaded length, with the .222 Remington Special to create a cartridge known as the .224E2 Winchester. With the U.S. military adoption of the ArmaLite AR-15
as the M16 rifle
in 1963, the .223 Remington was standardized as the 5.56×45mm. However, the .223 Remington was not introduced as a commercial sporting cartridge until 1964.
In a series of mock-combat situations testing in the early 1960s with the AR-15, M14
and AK-47
, the Army found that the AR-15's small size and light weight allowed it to be brought to bear much more quickly. Their final conclusion was that an 8-man team equipped with the AR-15 would have the same firepower as a current 11-man team armed with the M14. U.S. troops were able to carry more than twice as much 5.56×45mm ammunition as 7.62×51mm for the same weight, which would allow them a better advantage against a typical NVA
unit armed with AK-47s.
(*AK-47 magazines are much heavier than M14 and M16 magazines)
During the 1970s, NATO members signed an agreement to select a second, smaller caliber cartridge to replace the 7.62 mm NATO cartridge. Of the cartridges tendered, the 5.56x45mm was successful, but not the 55 gr M193 round used by the U.S. at that time. The wounds produced by the M193 round were so devastating that many consider it to be inhumane. Instead, the Belgian 62 gr SS109 round was chosen for standardization. The SS109 used a heavier bullet with a steel core and had a lower muzzle velocity for better long-range performance, specifically to meet a requirement that the bullet be able to penetrate through one side of a steel helmet at 600 meters. This requirement made the SS109 (M855) round less capable of fragmentation than the M193 and was considered more humane
(28.5 grains H2O) cartridge case capacity.
5.56×45mm NATO maximum NATO cartridge dimensions. All sizes in millimeters (mm).
Americans would define the shoulder angle at alpha/2 = 23 degrees. The common rifling
twist rate for this cartridge is 178 mm (1 in 7 in) or 229 mm (1 in 9 in), 6 grooves, Ø lands = 5.56 mm, Ø grooves = 5.69 mm, land width = 1.88 mm and the primer type
is small rifle.
According to the official NATO proofing guidelines the 5.56×45mm NATO case can handle up to 430 MPa (62,366.2 psi) piezo service pressure. In NATO regulated organizations every rifle cartridge combo has to be proofed
at 125% of this maximum pressure to certify for service issue. This is equal to the C.I.P. maximum pressure guideline for the .223 Remington
cartridge, that is the 5.56×45mm NATO parent cartridge.
The 5.56×45mm NATO cartridge with the standard military ball bullet
(NATO: SS109; U.S.: M855) will penetrate approximately 15 to 20 in (38.1 to 50.8 cm) into soft tissue in ideal circumstances. As with all spitzer
shaped projectiles it is prone to yaw in soft tissue. However, at impact velocities above roughly 2500 ft/s (762 m/s), it may yaw
and then fragment at the cannelure (the crimping groove around the cylinder of the bullet). These fragments can disperse through flesh and bone, inflicting additional internal injuries.
Fragmentation, if or when it occurs, imparts much greater damage to human tissue than bullet dimensions and velocities would suggest. This fragmentation effect is highly dependent on velocity, and therefore barrel
length: short-barreled carbines generate less muzzle velocity
and therefore lose wounding effectiveness at much shorter ranges than longer-barreled rifles. Proponents of the hydrostatic shock
theory contend that the rapid transfer of energy also results in wounding effects beyond the tissue directly crushed and torn by the bullet and fragments. These remote wounding effects are known as hydrostatic shock.
generates considerably less initial velocity than the longer 20" barrel found on the M16, and terminal performance can be a particular problem with the M4.
However, if the bullet is moving too slowly to reliably fragment on impact, the wound size and potential to incapacitate a person is greatly reduced. Several alternate cartridges have been developed in an attempt to address the perceived shortcomings of 5.56 mm ammunition including the 6.5 mm Grendel and the 6.8 mm Remington SPC
.
Recently, advances have been made in 5.56 mm ammunition. The US military has adopted for limited issue a 77-grain (5.0 g) "Match" bullet, type classified as the Mk 262. The heavy, lightly constructed bullet fragments more violently at short range and also has a longer fragmentation range. Originally designed for use in the Mk 12 SPR
, the ammunition has found favor with special forces units who were seeking a more effective cartridge to fire from their M4A1 carbines. Commercially available loadings using these heavier (and longer) bullets can be prohibitively expensive and cost much more than military surplus ammunition. Additionally, these heavy-for-caliber loadings sacrifice even more penetrative ability than the M855 round (which has a steel penetrator tip).
Performance of 5.56×45mm military ammunition can generally be categorized as almost entirely dependent upon velocity in order to wound effectively. Heavy OTM bullets enhance soft tissue wounding ability at the expense of hard-target/barrier penetration.
cartridges and chamberings are similar but not identical. Military 5.56mmx45 cases are often made thicker and therefore have less case capacity. However, the NATO specification allows a higher chamber pressure. NATO EPVAT
test barrels made for 5.56 mm NATO measure chamber pressure at the case mouth, as opposed to the location used by the United States civil standards organization SAAMI
. The piezoelectric sensor
s or transducers NATO and SAAMI use to conduct the actual pressure measurements also differ. This difference in measurement method accounts for upwards of 20000 psi (137.9 MPa) difference in pressure measurements. This means the NATO EPVAT maximum service pressure of 430 MPa (62,366.2 psi) for 5.56 mm NATO, is reduced by SAAMI to 55000 psi (379.2 MPa) for .223 Remington. In contrast to SAAMI, the other main civil standards organization C.I.P. defines the maximum service and proof test pressures of the .223 Remington cartridge equal to the 5.56 mm NATO.
The 5.56 mm NATO chambering, known as a NATO or mil-spec chamber, has a longer leade, which is the distance between the mouth of the cartridge and the point at which the rifling engages the bullet. The .223 Remington chambering, known as SAAMI chamber, is allowed to have a shorter leade, and is only required to be proof test
ed to the lower SAAMI chamber pressure. To address these issues, various proprietary chambers exist, such as the Wylde chamber (Rock River Arms) or the ArmaLite
chamber, which are designed to handle both 5.56 mm NATO and .223 Remington equally well. The dimensions and leade of the .223 Remington minimum C.I.P. chamber also differ from the 5.56 mm NATO chamber specification.
Using commercial .223 Remington cartridges in a 5.56 mm NATO chambered rifle should work reliably, but generally will not be as accurate as when fired from a .223 Remington chambered gun due to the longer leade. Using 5.56 mm NATO mil-spec cartridges (such as the M855) in a .223 Remington chambered rifle can lead to excessive wear and stress on the rifle and even be unsafe, and SAAMI recommends against the practice. Some commercial rifles marked as ".223 Remington" are in fact suited for 5.56 mm NATO, such as many commercial AR-15 variants and the Ruger Mini-14 (marked ".223 cal"), but the manufacturer should always be consulted to verify that this is acceptable before attempting it, and signs of excessive pressure (such as flattening or gas staining of the primers) should be looked for in the initial testing with 5.56 mm NATO ammunition.
It should also be noted that the upper receiver (to which the barrel with its chamber are attached) and the lower receiver are entirely separate parts in AR-15 style rifles. If the lower receiver has either .223 or 5.56 stamped on it, it does not guarantee the upper assembly is rated for the same caliber, because the upper and the lower receiver in the same rifle can, and frequently do, come from different manufacturers – particularly with rifles sold to civilians or second-hand rifles.
In more practical terms, as of 2010 most AR-15 parts suppliers engineer their complete upper assemblies (not to be confused with stripped uppers where the barrel is not included) to support both calibers in order to protect their customers from injuries and to protect their businesses from litigation following the said injuries.
NATO Ball (U.S.: M855) can penetrate up to 3 mm (about in) of steel at 600 meters. According to Nammo, a Norwegian ammunition producer, the M995 can penetrate up to 12 mm (nearly in) of RHA steel at 100 meters.
There have been numerous attempts to create an intermediate cartridge that addresses the complaints of 5.56 NATO's lack of stopping power along with lack of controllability seen in rifles firing 7.62 NATO in full auto. Other cartridges focused on superior short-range performance by sacrificing long-distance performance due to relatively short engagement distances typically observed in modern warfare. As of late 2009, none of those cartridges gained any significant traction beyond special forces
and sport shooting communities.
Examples include, but are not limited to: 6.8mm Remington SPC and 6.5mm Grendel.
Despite complaints that the 5.56 round lacks stopping power, others contend that animal studies of the wounding effects of the 5.56×45mm round versus the 7.62×39mm have found that the 5.56 mm round is more damaging, due to the post-impact behavior of the 5.56 mm projectile resulting in greater cavitation of soft tissues. The US Army contended in 2003 that the lack of close range lethality of the 5.56×45mm was more a matter of perception than fact. With controlled pairs and good shot placement to the head and chest, the target was usually defeated without issue. The majority of failures were the result of hitting the target in non-vital areas such as extremities. However, a minority of failures occurred in spite of multiple hits to the chest.
ball ammunition against certain types of targets (particularly hardened steel), blurring the performance differences that previously separated the two cartridges. The US Army Picatinny Arsenal
stated that the new M855A1 offers improved hard target capability, more consistent performance at all distances, enhanced dependability, improved accuracy, reduced muzzle flash, and higher velocity compared to the M855 round. Further the Army stated the new M855A1 ammunition is tailored for use in M4 carbine
s but should also give enhanced performance in M16 rifle
s and M249 light machine gun
s. The new 62-grain (4 g) projectile or bullet used in the M855A1 round has a copper core with a 19-grain (1.2 g) steel "stacked-cone" penetrating tip. The M855A1 cartridge is sometimes referred to as "green ammo" because it fires a lead free projectile.
The M855A1 was put on hold in August 2009 due to the experimental bismuth-tin
alloy core exhibiting undependable ballistics at high temperatures. The US Army has since replaced the bismuth-tin alloy core with one of solid copper eliminating the heat issue. The United States Marine Corps
purchased 1.8 million rounds in 2010, with plans to adopt the round to replace the interim MK318 SOST rounds used in Afghanistan when the M855A1 project was delayed.
The all-copper M855A1 gives consistent performance against soft targets while the wounding effects of the old M855 depended on the yaw angle measured at the point of flesh impact.
made originally for the Special Purpose Rifle (SPR)
. It uses a 77 gr bullet that is more effective at longer ranges than the standard issue M855 round.
Two versions of the round have been procured to date. Initial production runs, designated Mark 262 Mod 0, lacked a cannelure. Subsequent production, designated Mk 262 Mod 1, added a cannelure to the bullet for effective crimping.
According to US DoD sources, the Mk 262 round is capable of making kills at 700 meters. Ballistics tests found that the round caused "consistent initial yaw in soft tissue" at more than 300 meters. Apparently it is superior to the standard M855 round when fired from an M4 or M16 rifle. It evidently possesses superior stopping power, and can allow for engagements to be extended to up to 700 meters. It appears that this round can drastically improve the performance of any AR15 platform weapon chambered to .223/5.56 mm. Superior accuracy, wounding capacity, stopping power and range power has made this the preferred round of many Special Forces operators, and highly desirable as a replacement for the older, Belgian-designed 5.56×45mm M855 NATO round. Hard target penetration is slightly decreased.
The 5.6mm Gw Pat 90 or GP 90 (5.6 mm Rifle Cartridge 90), is the standard round used by the Swiss military
in its rifle, the SIG SG 550
. The cartridge is also known as the Cart 5.6mm F to the French and Italian speaking Swiss militiamen. The Swiss refer to the round as the 5.6 mm Gw Pat 90, although it is interchangeable with the 5.56×45mm NATO and .223 Remington
round. The Gw Pat 90 is optimized for use in 5.56 mm (.223 in) caliber barrels with a 254 mm (1:10 in) twist rate.
The Gw Pat 90 was designed for the SIG SG 550
when it came into production in 1987, replacing the SIG SG 510. Previous experience of a change in standard rifle had proved that changing the distance of fire for the training ranges was more expensive than the design of a new ammunition; this prompted the design of a cartridge nominally capable at 300 meters. The cartridge was also designed to reduce pollution by controlling lead emissions. The bullet was originally clad with a nickel alloy jacket, however, this was found to cause excessive barrel wear, so in 1998 the nickel jackets were replaced with tombac
jackets. In addition, in 1999 a copper plug was added to the base of the bullet to address environmental concerns.
The ammunition is currently (2009) produced by RUAG Ammotec, a subsidiary
of the RUAG group
. The ammunition is manufactured in three variations: the standard FMJ round, the tracer round, and a blank round.
The FMJ cartridge has a CuZn-alloy case and uses a double base propellant. The bullet is a 4.1 g (63 gr) tombac
jacketed FMJ
projectile with a G1 ballistic coefficient
of 0.331 (ICAO) / 0.337 (Army Metro). The projectile contains approximately 95% Pb, 2% Sb, 3% Cu, and was designed for terminal ballistic instability. The required accuracy for Gw Pat 90 ammunition out of factory test barrels is 63 mm (0.72 MOA
) for 10 rounds (100% radius measurement method) out to 300 m. The Gw Pat 90 cartridge dimensions are in accordance with the civilian C.I.P. standards for the .223 Remington C.I.P. chambering.
The Gw Pat 90 is used both in the Swiss military and in sport shooting. The very high level of individual training in the Swiss militia (every single soldier bearing a weapon has to shoot for qualification once a year; see Gun politics in Switzerland
) and the overall use of the Gw Pat 90 by the many Swiss citizens who shoot in competitions and for amusement has resulted in significant input on its usage. Over 1 billion cartridges have been produced as of 2005.
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...
cartridge
Cartridge (firearms)
A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...
developed in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and originally chambered in the M16 rifle
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...
. Under STANAG
STANAG
STANAG is the NATO abbreviation for Standardization Agreement, which sets up processes, procedures, terms, and conditions for common military or technical procedures or equipment between the member countries of the alliance. Each NATO state ratifies a STANAG and implements it within their own...
4172, it is a standard cartridge for NATO forces as well as many non-NATO countries. It is derived from, but not identical to, the .223 Remington
.223 Remington
The .223 Remington is a sporting cartridge with almost the same external dimensions as the 5.56×45mm NATO military cartridge. The name is commonly pronounced either two-two-three or two-twenty-three. It is loaded with a diameter, jacketed bullet, with weights ranging from , though the most common...
cartridge. When the bullet impacts at high velocity and yaw
Yaw
The word yaw can refer to:* Yaw angle, one of the Tait-Bryan angles, describing the heading of a vehicle or machine, and some other related elements:**Yaw system, component responsible for the orientation of a wind turbine towards the wind....
s in tissue, fragmentation creates a rapid transfer of energy which can result in dramatic wounding effects.
History
The previous standard NATO rifle cartridge was the 7.62×51mm NATO7.62×51mm NATO
The 7.62×51mm NATO is a rifle cartridge developed in the 1950s as a standard for small arms among NATO countries...
, derived from the .308 Winchester
.308 Winchester
The .308 Winchester is a rifle cartridge and is the commercial cartridge upon which the military 7.62x51mm NATO centerfire cartridge is based. The .308 Winchester was introduced in 1952, two years prior to the NATO adoption of the 7.62x51mm NATO T65...
rifle cartridge and designed to replace the U.S. military's .30-06 Springfield
.30-06 Springfield
The .30-06 Springfield cartridge or 7.62×63mm in metric notation, was introduced to the United States Army in 1906 and standardized, and was in use until the 1960s and early 1970s. It replaced the .30-03, 6 mm Lee Navy, and .30 US Army...
rifle cartridge. At the time of selection, there had been criticism that the 7.62 mm was too powerful for modern service rifle
Service rifle
The service rifle of a given army or armed force is that which it issues as standard to its soldiers. In modern forces, this is typically a highly versatile and rugged assault rifle suitable for use in nearly all theatres and environments...
s, causing excessive recoil, and that the weight of the ammunition did not allow for enough rate of fire
Rate of fire
Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. It is usually measured in rounds per minute , or per second .-Overview:...
in modern combat.
The British had extensive evidence with their own experiments into an intermediate cartridge since 1945 and were on the point of introducing a .280 inch (7 mm) cartridge
.280 British
The .280 British was an experimental intermediate rifle cartridge. It was later designated 7 mm MK1Z, and has also been known as 7 mm NATO, .280/30, .280 Enfield, .280 NATO, 7 mm FN Short, and 7×43mm. It was designed by the British Army in the late 1940s, with subsequent help from...
when the selection of the 7.62 mm NATO was made. The FN
Fabrique Nationale de Herstal
Fabrique Nationale d'Herstal — self identified as FN Herstal and often referred to as Fabrique Nationale or simply FN — is a firearms manufacturer located in Herstal, Belgium....
company had also been involved. The concerns about recoil and effectiveness were effectively overruled by the US within NATO, and the other NATO nations accepted that standardization was more important at the time than selection of the ideal cartridge. However the concerns would prove to be valid and led to the development of the 5.56 cartridge.
During the late 1950s, ArmaLite
ArmaLite
ArmaLite is the name of a small arms engineering facility founded in the early 1950s, and once associated with the Fairchild Engine and Airplane Corporation. ArmaLite was formally incorporated as a subdivision of Fairchild on October 1, 1954...
and other U.S. firearm
Firearm
A firearm is a weapon that launches one, or many, projectile at high velocity through confined burning of a propellant. This subsonic burning process is technically known as deflagration, as opposed to supersonic combustion known as a detonation. In older firearms, the propellant was typically...
designers started their individual Small Caliber/High Velocity (SCHV) assault rifle experiments using the commercial .222 Remington
.222 Remington
The .222 Remington aka the Triple Deuce/Triple Two/Treble Two is a centerfire rifle cartridge introduced in 1950, and was the first commercial rimless .22 cartridge made in the United States...
cartridge. When it became clear that there was not enough powder capacity to meet U.S. Continental Army Command's (CONARC) velocity and penetration requirements, ArmaLite contacted Remington to create a similar cartridge with a longer case body and shorter neck. This became the .222 Remington Special. At the same time, Springfield Armory
Springfield Armory
The Springfield Armory, located in the City of Springfield, Massachusetts - from 1777 until its closing in 1968 - was the primary center for the manufacture of U.S. military firearms. After its controversial closing during the Vietnam War, the Springfield Armory was declared Western Massachusetts'...
's Earle Harvey had Remington create an even longer cartridge case then known as the .224 Springfield. Springfield was forced to drop out of the CONARC competition, and thus the .224 Springfield was later released as a commercial sporting cartridge known as the .222 Remington Magnum
.222 Remington Magnum
The .222 Remington Magnum was a short-lived commercially produced cartridge derived from the .222 Remington. Originally developed for a US prototype military rifle in 1958, the cartridge was not adopted by the military, but was introduced commercially in sporting rifles.-Development:The .222 Rem....
. To prevent confusion with all of the competing .222 cartridge designations, the .222 Remington Special was renamed the .223 Remington
.223 Remington
The .223 Remington is a sporting cartridge with almost the same external dimensions as the 5.56×45mm NATO military cartridge. The name is commonly pronounced either two-two-three or two-twenty-three. It is loaded with a diameter, jacketed bullet, with weights ranging from , though the most common...
. After playing with their own proprietary cartridge case design, the .224E1 Winchester, Winchester eventually standardized their case dimensions, but not overall loaded length, with the .222 Remington Special to create a cartridge known as the .224E2 Winchester. With the U.S. military adoption of the ArmaLite AR-15
AR-15
The AR-15 is a lightweight, 5.56 mm, air-cooled, gas-operated, magazine-fed semi-automatic rifle, with a rotating-lock bolt, actuated by direct impingement gas operation. It is manufactured with the extensive use of aluminum alloys and synthetic materials....
as the M16 rifle
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...
in 1963, the .223 Remington was standardized as the 5.56×45mm. However, the .223 Remington was not introduced as a commercial sporting cartridge until 1964.
In a series of mock-combat situations testing in the early 1960s with the AR-15, M14
M14 rifle
The M14 rifle, formally the United States Rifle, 7.62 mm, M14, is an American selective fire automatic rifle firing 7.62x51mm NATO ammunition. It was the standard issue U.S. rifle from 1959 to 1970. The M14 was used for U.S...
and AK-47
AK-47
The AK-47 is a selective-fire, gas-operated 7.62×39mm assault rifle, first developed in the Soviet Union by Mikhail Kalashnikov. It is officially known as Avtomat Kalashnikova . It is also known as a Kalashnikov, an "AK", or in Russian slang, Kalash.Design work on the AK-47 began in the last year...
, the Army found that the AR-15's small size and light weight allowed it to be brought to bear much more quickly. Their final conclusion was that an 8-man team equipped with the AR-15 would have the same firepower as a current 11-man team armed with the M14. U.S. troops were able to carry more than twice as much 5.56×45mm ammunition as 7.62×51mm for the same weight, which would allow them a better advantage against a typical NVA
Vietnam People's Army
The Vietnam People's Army is the armed forces of Vietnam. The VPA includes: the Vietnamese People's Ground Forces , the Vietnam People's Navy , the Vietnam People's Air Force, and the Vietnam Marine Police.During the French Indochina War , the VPA was often referred to as the Việt...
unit armed with AK-47s.
| Rifle | Cartridge | Cartridge weight | Weight of loaded magazine | Max. 10 kilogram ammo load |
|---|---|---|---|---|
| M14 | 7.62×51mm 7.62×51mm NATO The 7.62×51mm NATO is a rifle cartridge developed in the 1950s as a standard for small arms among NATO countries... |
393 gr | 20 rd mag @ 0.68 kg | 14 mags @ 9.52 kg for 280 rds |
| M16 | 5.56×45mm | 183 gr | 20 rd mag @ 0.3 kg | 33 mags @ 9.9 kg for 660 rds |
| AK-47 | 7.62×39mm 7.62×39mm The 7.62×39mm round is a rifle cartridge of Soviet origin that was designed during World War II. It was first used in the RPD machine gun. Due to the worldwide proliferation of the SKS and AK-47 pattern rifles, the cartridge is utilized by both militaries and civilians alike.The 7.62×39mm... |
281 gr | 30 rd mag @ 0.92 kg* | 10 mags @ 9.2 kg for 300 rds |
(*AK-47 magazines are much heavier than M14 and M16 magazines)
During the 1970s, NATO members signed an agreement to select a second, smaller caliber cartridge to replace the 7.62 mm NATO cartridge. Of the cartridges tendered, the 5.56x45mm was successful, but not the 55 gr M193 round used by the U.S. at that time. The wounds produced by the M193 round were so devastating that many consider it to be inhumane. Instead, the Belgian 62 gr SS109 round was chosen for standardization. The SS109 used a heavier bullet with a steel core and had a lower muzzle velocity for better long-range performance, specifically to meet a requirement that the bullet be able to penetrate through one side of a steel helmet at 600 meters. This requirement made the SS109 (M855) round less capable of fragmentation than the M193 and was considered more humane
Cartridge dimensions
The 5.56×45mm NATO has 1.85 mlLitre
pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...
(28.5 grains H2O) cartridge case capacity.
5.56×45mm NATO maximum NATO cartridge dimensions. All sizes in millimeters (mm).
Americans would define the shoulder angle at alpha/2 = 23 degrees. The common rifling
Rifling
Rifling is the process of making helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis...
twist rate for this cartridge is 178 mm (1 in 7 in) or 229 mm (1 in 9 in), 6 grooves, Ø lands = 5.56 mm, Ø grooves = 5.69 mm, land width = 1.88 mm and the primer type
Percussion cap
The percussion cap, introduced around 1830, was the crucial invention that enabled muzzleloading firearms to fire reliably in any weather.Before this development, firearms used flintlock ignition systems which produced flint-on-steel sparks to ignite a pan of priming powder and thereby fire the...
is small rifle.
According to the official NATO proofing guidelines the 5.56×45mm NATO case can handle up to 430 MPa (62,366.2 psi) piezo service pressure. In NATO regulated organizations every rifle cartridge combo has to be proofed
Proof test
A proof test is a test wherein a deliberately over-pressured round is fired from a firearm in order to verify that the firearm is not defective and will not explode on firing. The firearm is inspected after the test, and if it is found to be in sound condition, then it is marked with a proof mark...
at 125% of this maximum pressure to certify for service issue. This is equal to the C.I.P. maximum pressure guideline for the .223 Remington
.223 Remington
The .223 Remington is a sporting cartridge with almost the same external dimensions as the 5.56×45mm NATO military cartridge. The name is commonly pronounced either two-two-three or two-twenty-three. It is loaded with a diameter, jacketed bullet, with weights ranging from , though the most common...
cartridge, that is the 5.56×45mm NATO parent cartridge.
Performance
Full metal jacket bullet
A full metal jacket is a bullet consisting of a soft core 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, or often just the front and sides with the rear left as exposed lead...
(NATO: SS109; U.S.: M855) will penetrate approximately 15 to 20 in (38.1 to 50.8 cm) into soft tissue in ideal circumstances. As with all spitzer
Spitzer (bullet)
A spitzer, also commonly referred to as a spire point bullet, is an aerodynamic bullet design used in most intermediate and high-powered rifle cartridges...
shaped projectiles it is prone to yaw in soft tissue. However, at impact velocities above roughly 2500 ft/s (762 m/s), it may yaw
Flight dynamics
Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...
and then fragment at the cannelure (the crimping groove around the cylinder of the bullet). These fragments can disperse through flesh and bone, inflicting additional internal injuries.
Fragmentation, if or when it occurs, imparts much greater damage to human tissue than bullet dimensions and velocities would suggest. This fragmentation effect is highly dependent on velocity, and therefore barrel
Gun barrel
A gun barrel is the tube, usually metal, through which a controlled explosion or rapid expansion of gases are released in order to propel a projectile out of the end at a high velocity....
length: short-barreled carbines generate less muzzle velocity
Muzzle velocity
Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. Muzzle velocities range from approximately to in black powder muskets , to more than in modern rifles with high-performance cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns...
and therefore lose wounding effectiveness at much shorter ranges than longer-barreled rifles. Proponents of the hydrostatic shock
Hydrostatic shock
Hydrostatic shock or hydraulic shock describes the observation that a penetrating projectile can produce remote wounding and incapacitating effects in living targets through a hydraulic effect in their liquid-filled tissues, in addition to local effects in tissue caused by direct impact...
theory contend that the rapid transfer of energy also results in wounding effects beyond the tissue directly crushed and torn by the bullet and fragments. These remote wounding effects are known as hydrostatic shock.
Criticism
There has been much criticism of the poor performance of the bullet on target, especially the first-shot kill rate when the muzzle velocity of the used firearms and the downrange bullet deceleration do not achieve the minimally required terminal velocity at the target to cause fragmentation. This wounding problem has been cited in incidents beginning in the first Gulf war, Somalia, and in the current conflicts in Iraq and Afghanistan. In recent lab testing of M855, it has been shown that the bullets do not fragment reliably or consistently from round-to-round, displaying widely variable performance. In several cases, yawing did not begin until 7–10 in of penetration. This was with all rounds coming from the same manufacturer. This lack of wounding capacity typically becomes an increasingly significant issue as range increases (e.g., ranges over 50 m when using an M4 or 200 m when using an M16) or when penetrating heavy clothing, but this problem is compounded in shorter-barreled weapons. The 14.5 inches (36.8 cm) barrel of the U.S. military's M4 carbineM4 carbine
The M4 carbine is a family of firearms tracing its lineage back to earlier carbine versions of the M16, all based on the original AR-15 designed by Eugene Stoner and made by ArmaLite. It is a shorter and lighter variant of the M16A2 assault rifle, with 80% parts commonality.It is a gas-operated,...
generates considerably less initial velocity than the longer 20" barrel found on the M16, and terminal performance can be a particular problem with the M4.
However, if the bullet is moving too slowly to reliably fragment on impact, the wound size and potential to incapacitate a person is greatly reduced. Several alternate cartridges have been developed in an attempt to address the perceived shortcomings of 5.56 mm ammunition including the 6.5 mm Grendel and the 6.8 mm Remington SPC
6.8 mm Remington SPC
The 6.8 mm Remington SPC is a rifle cartridge that was developed with collaboration from individual members of United States Special Operations Command . Based upon the .30 Remington cartridge, it is midway between the 5.56×45mm NATO and 7.62×51mm NATO in bore diameter and velocity...
.
Recently, advances have been made in 5.56 mm ammunition. The US military has adopted for limited issue a 77-grain (5.0 g) "Match" bullet, type classified as the Mk 262. The heavy, lightly constructed bullet fragments more violently at short range and also has a longer fragmentation range. Originally designed for use in the Mk 12 SPR
United States Navy Mark 12 Mod X Special Purpose Rifle
The United States Navy Mark 12 Mod 0/1 Special Purpose Rifle is a rifle in service with United States Special Operations Forces in Operation Enduring Freedom and Operation Iraqi Freedom...
, the ammunition has found favor with special forces units who were seeking a more effective cartridge to fire from their M4A1 carbines. Commercially available loadings using these heavier (and longer) bullets can be prohibitively expensive and cost much more than military surplus ammunition. Additionally, these heavy-for-caliber loadings sacrifice even more penetrative ability than the M855 round (which has a steel penetrator tip).
Performance of 5.56×45mm military ammunition can generally be categorized as almost entirely dependent upon velocity in order to wound effectively. Heavy OTM bullets enhance soft tissue wounding ability at the expense of hard-target/barrier penetration.
5.56 mm NATO versus .223 Remington
The 5.56 mm NATO and .223 Remington.223 Remington
The .223 Remington is a sporting cartridge with almost the same external dimensions as the 5.56×45mm NATO military cartridge. The name is commonly pronounced either two-two-three or two-twenty-three. It is loaded with a diameter, jacketed bullet, with weights ranging from , though the most common...
cartridges and chamberings are similar but not identical. Military 5.56mmx45 cases are often made thicker and therefore have less case capacity. However, the NATO specification allows a higher chamber pressure. NATO EPVAT
NATO EPVAT testing
NATO EPVAT testing is one of the three recognized classes of procedures used in the world to control the safety and quality of firearms ammunition....
test barrels made for 5.56 mm NATO measure chamber pressure at the case mouth, as opposed to the location used by the United States civil standards organization SAAMI
Sporting Arms and Ammunition Manufacturers' Institute
The Sporting Arms and Ammunition Manufacturers' Institute is an association of American firearms and ammunition manufacturers...
. The piezoelectric sensor
Piezoelectric sensor
A piezoelectric sensor is a device that uses the piezoelectric effect to measure pressure, acceleration, strain or force by converting them to an electrical charge.-Applications:...
s or transducers NATO and SAAMI use to conduct the actual pressure measurements also differ. This difference in measurement method accounts for upwards of 20000 psi (137.9 MPa) difference in pressure measurements. This means the NATO EPVAT maximum service pressure of 430 MPa (62,366.2 psi) for 5.56 mm NATO, is reduced by SAAMI to 55000 psi (379.2 MPa) for .223 Remington. In contrast to SAAMI, the other main civil standards organization C.I.P. defines the maximum service and proof test pressures of the .223 Remington cartridge equal to the 5.56 mm NATO.
The 5.56 mm NATO chambering, known as a NATO or mil-spec chamber, has a longer leade, which is the distance between the mouth of the cartridge and the point at which the rifling engages the bullet. The .223 Remington chambering, known as SAAMI chamber, is allowed to have a shorter leade, and is only required to be proof test
Proof test
A proof test is a test wherein a deliberately over-pressured round is fired from a firearm in order to verify that the firearm is not defective and will not explode on firing. The firearm is inspected after the test, and if it is found to be in sound condition, then it is marked with a proof mark...
ed to the lower SAAMI chamber pressure. To address these issues, various proprietary chambers exist, such as the Wylde chamber (Rock River Arms) or the ArmaLite
ArmaLite
ArmaLite is the name of a small arms engineering facility founded in the early 1950s, and once associated with the Fairchild Engine and Airplane Corporation. ArmaLite was formally incorporated as a subdivision of Fairchild on October 1, 1954...
chamber, which are designed to handle both 5.56 mm NATO and .223 Remington equally well. The dimensions and leade of the .223 Remington minimum C.I.P. chamber also differ from the 5.56 mm NATO chamber specification.
Using commercial .223 Remington cartridges in a 5.56 mm NATO chambered rifle should work reliably, but generally will not be as accurate as when fired from a .223 Remington chambered gun due to the longer leade. Using 5.56 mm NATO mil-spec cartridges (such as the M855) in a .223 Remington chambered rifle can lead to excessive wear and stress on the rifle and even be unsafe, and SAAMI recommends against the practice. Some commercial rifles marked as ".223 Remington" are in fact suited for 5.56 mm NATO, such as many commercial AR-15 variants and the Ruger Mini-14 (marked ".223 cal"), but the manufacturer should always be consulted to verify that this is acceptable before attempting it, and signs of excessive pressure (such as flattening or gas staining of the primers) should be looked for in the initial testing with 5.56 mm NATO ammunition.
It should also be noted that the upper receiver (to which the barrel with its chamber are attached) and the lower receiver are entirely separate parts in AR-15 style rifles. If the lower receiver has either .223 or 5.56 stamped on it, it does not guarantee the upper assembly is rated for the same caliber, because the upper and the lower receiver in the same rifle can, and frequently do, come from different manufacturers – particularly with rifles sold to civilians or second-hand rifles.
In more practical terms, as of 2010 most AR-15 parts suppliers engineer their complete upper assemblies (not to be confused with stripped uppers where the barrel is not included) to support both calibers in order to protect their customers from injuries and to protect their businesses from litigation following the said injuries.
Comparison of 5.56mm NATO versus 7.62mm NATO
| Cartridge | Model | Cartridge size | Cartridge weight | Bullet weight | Velocity | Energy |
|---|---|---|---|---|---|---|
| 5.56mm NATO | M855 | 5.56×45mm | 12.31 g (190 gr) | 4.02 g (62 gr) | 945.5 m/s (3,100 ft/s) | 1,797 J |
| 7.62mm NATO 7.62×51mm NATO The 7.62×51mm NATO is a rifle cartridge developed in the 1950s as a standard for small arms among NATO countries... |
M80 | 7.62×51mm | 25.40 g (392 gr) | 9.33 g (147 gr) | 838.0 m/s (2,749 ft/s) | 3,275 J |
NATO Ball (U.S.: M855) can penetrate up to 3 mm (about in) of steel at 600 meters. According to Nammo, a Norwegian ammunition producer, the M995 can penetrate up to 12 mm (nearly in) of RHA steel at 100 meters.
There have been numerous attempts to create an intermediate cartridge that addresses the complaints of 5.56 NATO's lack of stopping power along with lack of controllability seen in rifles firing 7.62 NATO in full auto. Other cartridges focused on superior short-range performance by sacrificing long-distance performance due to relatively short engagement distances typically observed in modern warfare. As of late 2009, none of those cartridges gained any significant traction beyond special forces
Special forces
Special forces, or special operations forces are terms used to describe elite military tactical teams trained to perform high-risk dangerous missions that conventional units cannot perform...
and sport shooting communities.
Examples include, but are not limited to: 6.8mm Remington SPC and 6.5mm Grendel.
Despite complaints that the 5.56 round lacks stopping power, others contend that animal studies of the wounding effects of the 5.56×45mm round versus the 7.62×39mm have found that the 5.56 mm round is more damaging, due to the post-impact behavior of the 5.56 mm projectile resulting in greater cavitation of soft tissues. The US Army contended in 2003 that the lack of close range lethality of the 5.56×45mm was more a matter of perception than fact. With controlled pairs and good shot placement to the head and chest, the target was usually defeated without issue. The majority of failures were the result of hitting the target in non-vital areas such as extremities. However, a minority of failures occurred in spite of multiple hits to the chest.
Military cartridge types
- Cartridge, Ball, F1 (Australia): 5.56×45mm FN SS109 equivalent produced by Australian Defence Industries(ADI), now Thales Australia.
- Cartridge, Blank, F3 (Australia): 5.56×45mm Blank cartridge produced by Australian Defence Industries(ADI), now Thales Australia.
- Cartridge, Ball, C77 (Canada): 5.56×45mm FN SS109 equivalent used in the C7, C8 and C9FN MinimiThe Minimi is a Belgian 5.56mm light machine gun developed by Fabrique Nationale in Herstal by Ernest Vervier. First introduced in 1974, it has entered service with the armed forces of over thirty countries...
type weapons. - Cartridge, Blank, C79 (Canada): 5.56×45mm blank cartridge used in the C7, C8 and C9 type weapons.
- Cartridge, Ball, DM11 (Germany): 5.56×45mm 4.1 g dual core ball cartridge, green tip w/steel core, produced by RUAGRUAGRUAG is a Swiss technology company, with its headquarters in Bern. It has production sites in Switzerland , Germany , Sweden , Hungary and Austria .-Structure:The RUAG has following subsidiaries:*RUAG Aerospace RUAG is a Swiss technology company, with its headquarters in Bern. It has production...
Ammotec. - Cartridge, Tracer, DM21 (Germany): 5.56×45mm tracer compliment to DM11, also produced by RUAGRUAGRUAG is a Swiss technology company, with its headquarters in Bern. It has production sites in Switzerland , Germany , Sweden , Hungary and Austria .-Structure:The RUAG has following subsidiaries:*RUAG Aerospace RUAG is a Swiss technology company, with its headquarters in Bern. It has production...
Ammotec. - Cartridge, Ball, L2A1 (United Kingdom): 5.56×45mm FN SS109 equivalent produced by Radway Green.
- Cartridge, Tracer, L1A1 (United Kingdom): 5.56×45mm tracer compliment to L2A1, also produced by Radway Green.
- Cartridge, Caliber 5.56 mm, Ball, M193 (United States): 5.56×45mm 55-grain ball cartridge.
- Cartridge, Caliber 5.56 mm, Grenade, M195 (United States): 5.56×45mm grenade launching blank.
- Cartridge, Caliber 5.56 mm, Tracer, M196 (United States): 5.56×45mm 54-grain tracer cartridge, red cartridge tip.
- Cartridge, Caliber 5.56 mm, Dummy, M199 (United States): 5.56x45mm dummy cartridge, non firing, indented case.
- Cartridge, Caliber 5.56 mm, Blank, M200 (United States): 5.56×45mm violet-tipped blank cartridge.
- Cartridge, Caliber 5.56 mm, Ball, M202 (United States): 5.56×45mm 58-grain FN SSX822 cartridge
- Cartridge, Caliber 5.56 mm, Ball, XM287 (United States): 5.56×45mm 68-grain ball cartridge produced by Industries Valcartier, Inc. An Improved version was also produced designated XM779.
- Cartridge, Caliber 5.56 mm, Tracer, XM288 (United States): 5.56×45mm 68-grain tracer cartridge produced by Industries Valcartier, Inc. An Improved version was also produced designated XM780.
- Cartridge, Caliber 5.56 mm, Grenade, M755 (United States): 5.56×45mm grenade launching blank specifically for the M234 launcher.
- Cartridge, Caliber 5.56 mm, Ball, XM777 (United States): 5.56×45mm ball cartridge.
- Cartridge, Caliber 5.56 mm, Tracer, XM778 (United States): 5.56×45mm tracer cartridge.
- Cartridge, Caliber 5.56 mm, Ball, M855 (United States): 5.56×45mm 62-grain FN SS109 ball cartridge, green tip w/steel penetrator and a lead core.
- Cartridge, Caliber 5.56 mm, Ball, M855 Lead Free (United States):62-grain green tip w/tungsten penetrator and a steel core. Primarily used during training in countries with strict lead disposal laws.
- Cartridge, Caliber 5.56 mm, Ball, M855A1 (United States):62-grain green tip w/19-grain steel penetrator tip and a solid copper core.
- Cartridge, Caliber 5.56 mm, Tracer, M856 (United States): 5.56×45mm 64-grain FN L110 tracer cartridge
- Cartridge, Caliber 5.56 mm, Armor Piercing, M995 (United States): 5.56×45mm 52-grain AP cartridge, black cartridge tip.
- Cartridge, Caliber 5.56 mm, Tracer, XM996 (United States): 5.56×45mm so-called "Dim Tracer" with reduced effect primarily for use with night vision devices.
- Cartridge, Caliber 5.56 mm, Special Ball, Long Range, Mk 262 Mod 0/1 (United States): 5.56×45mm 77-grain Open-Tipped Match/Hollow-Point Boat-Tail cartridge. Mod 0 features Sierra Matchking bullet, while Mod 1 features either Nosler or Sierra bullet.
- Cartridge, Caliber 5.56 mm, MK318 MOD 0 enhanced 5.56 mm ammunition (United States): 5.56×45mm 62-grain Open-Tipped Match Boat-Tail cartridge.
- Cartridge, 5.64 mm, Ball, MLU-26/P (United States): Early USAF designation for 5.56×45mm ball cartridge produced by Remington.
M855A1
June 2010, the United States Army announced it began shipping its new 5.56 mm cartridge, the M855A1 Enhanced Performance Round, to active combat zones. During testing, the M855A1 performed better than current 7.62×51mm NATO7.62×51mm NATO
The 7.62×51mm NATO is a rifle cartridge developed in the 1950s as a standard for small arms among NATO countries...
ball ammunition against certain types of targets (particularly hardened steel), blurring the performance differences that previously separated the two cartridges. The US Army Picatinny Arsenal
Picatinny Arsenal
The Picatinny Arsenal is an American military research and manufacturing facility located on a lot in northern New Jersey near Lake Denmark. The Arsenal is the headquarters of the United States Army Armament Research, Development and Engineering Center...
stated that the new M855A1 offers improved hard target capability, more consistent performance at all distances, enhanced dependability, improved accuracy, reduced muzzle flash, and higher velocity compared to the M855 round. Further the Army stated the new M855A1 ammunition is tailored for use in M4 carbine
M4 carbine
The M4 carbine is a family of firearms tracing its lineage back to earlier carbine versions of the M16, all based on the original AR-15 designed by Eugene Stoner and made by ArmaLite. It is a shorter and lighter variant of the M16A2 assault rifle, with 80% parts commonality.It is a gas-operated,...
s but should also give enhanced performance in M16 rifle
M16 rifle
The M16 is the United States military designation for the AR-15 rifle adapted for both semi-automatic and full-automatic fire. Colt purchased the rights to the AR-15 from ArmaLite, and currently uses that designation only for semi-automatic versions of the rifle. The M16 fires the 5.56×45mm NATO...
s and M249 light machine gun
M249 light machine gun
The M249 light machine gun , previously designated the M249 Squad Automatic Weapon , and formally written as Light Machine Gun, 5.56 mm, M249, is an American version of the Belgian FN Minimi, a light machine gun manufactured by the Belgian company FN Herstal . The M249 is manufactured in the...
s. The new 62-grain (4 g) projectile or bullet used in the M855A1 round has a copper core with a 19-grain (1.2 g) steel "stacked-cone" penetrating tip. The M855A1 cartridge is sometimes referred to as "green ammo" because it fires a lead free projectile.
The M855A1 was put on hold in August 2009 due to the experimental bismuth-tin
Bismuth
Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...
alloy core exhibiting undependable ballistics at high temperatures. The US Army has since replaced the bismuth-tin alloy core with one of solid copper eliminating the heat issue. The United States Marine Corps
United States Marine Corps
The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...
purchased 1.8 million rounds in 2010, with plans to adopt the round to replace the interim MK318 SOST rounds used in Afghanistan when the M855A1 project was delayed.
The all-copper M855A1 gives consistent performance against soft targets while the wounding effects of the old M855 depended on the yaw angle measured at the point of flesh impact.
Mk 262
The Mk 262 is a match quality round manufactured by Black Hills AmmunitionBlack Hills Ammunition
Black Hills Ammunition is an American ammunition and reloading supplies manufacturing company based in Rapid City, South Dakota. Black Hills is popular among Cowboy Action Shooters because they produce quality ammunition in a number of obsolete calibers, such as .44 Russian, .38 Long Colt, .44-40...
made originally for the Special Purpose Rifle (SPR)
United States Navy Mark 12 Mod X Special Purpose Rifle
The United States Navy Mark 12 Mod 0/1 Special Purpose Rifle is a rifle in service with United States Special Operations Forces in Operation Enduring Freedom and Operation Iraqi Freedom...
. It uses a 77 gr bullet that is more effective at longer ranges than the standard issue M855 round.
Two versions of the round have been procured to date. Initial production runs, designated Mark 262 Mod 0, lacked a cannelure. Subsequent production, designated Mk 262 Mod 1, added a cannelure to the bullet for effective crimping.
According to US DoD sources, the Mk 262 round is capable of making kills at 700 meters. Ballistics tests found that the round caused "consistent initial yaw in soft tissue" at more than 300 meters. Apparently it is superior to the standard M855 round when fired from an M4 or M16 rifle. It evidently possesses superior stopping power, and can allow for engagements to be extended to up to 700 meters. It appears that this round can drastically improve the performance of any AR15 platform weapon chambered to .223/5.56 mm. Superior accuracy, wounding capacity, stopping power and range power has made this the preferred round of many Special Forces operators, and highly desirable as a replacement for the older, Belgian-designed 5.56×45mm M855 NATO round. Hard target penetration is slightly decreased.
5.6mm Gw Pat 90
Military of Switzerland
The Swiss Armed Forces perform the roles of Switzerland's militia and regular army. Under the country's militia system, professional soldiers constitute about 5 percent of military personnel; the rest are male citizen conscripts 19 to 34 years old...
in its rifle, the SIG SG 550
SIG SG 550
The SG 550 is an assault rifle manufactured by Swiss Arms AG of Neuhausen, Switzerland...
. The cartridge is also known as the Cart 5.6mm F to the French and Italian speaking Swiss militiamen. The Swiss refer to the round as the 5.6 mm Gw Pat 90, although it is interchangeable with the 5.56×45mm NATO and .223 Remington
.223 Remington
The .223 Remington is a sporting cartridge with almost the same external dimensions as the 5.56×45mm NATO military cartridge. The name is commonly pronounced either two-two-three or two-twenty-three. It is loaded with a diameter, jacketed bullet, with weights ranging from , though the most common...
round. The Gw Pat 90 is optimized for use in 5.56 mm (.223 in) caliber barrels with a 254 mm (1:10 in) twist rate.
The Gw Pat 90 was designed for the SIG SG 550
SIG SG 550
The SG 550 is an assault rifle manufactured by Swiss Arms AG of Neuhausen, Switzerland...
when it came into production in 1987, replacing the SIG SG 510. Previous experience of a change in standard rifle had proved that changing the distance of fire for the training ranges was more expensive than the design of a new ammunition; this prompted the design of a cartridge nominally capable at 300 meters. The cartridge was also designed to reduce pollution by controlling lead emissions. The bullet was originally clad with a nickel alloy jacket, however, this was found to cause excessive barrel wear, so in 1998 the nickel jackets were replaced with tombac
Tombac
Tombac, as spelled in French, or Tombak is a brass alloy with high copper content and 5-20% zinc content. Tin, lead or arsenic may be added for colouration.It is a cheap malleable alloy mainly used for medals, ornament, decoration and some munitions....
jackets. In addition, in 1999 a copper plug was added to the base of the bullet to address environmental concerns.
The ammunition is currently (2009) produced by RUAG Ammotec, a subsidiary
Subsidiary
A subsidiary company, subsidiary, or daughter company is a company that is completely or partly owned and wholly controlled by another company that owns more than half of the subsidiary's stock. The subsidiary can be a company, corporation, or limited liability company. In some cases it is a...
of the RUAG group
RUAG
RUAG is a Swiss technology company, with its headquarters in Bern. It has production sites in Switzerland , Germany , Sweden , Hungary and Austria .-Structure:The RUAG has following subsidiaries:*RUAG Aerospace RUAG is a Swiss technology company, with its headquarters in Bern. It has production...
. The ammunition is manufactured in three variations: the standard FMJ round, the tracer round, and a blank round.
The FMJ cartridge has a CuZn-alloy case and uses a double base propellant. The bullet is a 4.1 g (63 gr) tombac
Tombac
Tombac, as spelled in French, or Tombak is a brass alloy with high copper content and 5-20% zinc content. Tin, lead or arsenic may be added for colouration.It is a cheap malleable alloy mainly used for medals, ornament, decoration and some munitions....
jacketed FMJ
Full metal jacket bullet
A full metal jacket is a bullet consisting of a soft core 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, or often just the front and sides with the rear left as exposed lead...
projectile with a G1 ballistic coefficient
Ballistic coefficient
In ballistics, the ballistic coefficient of a body is a measure of its ability to overcome air resistance in flight. It is inversely proportional to the negative acceleration—a high number indicates a low negative acceleration. BC is a function of mass, diameter, and drag coefficient...
of 0.331 (ICAO) / 0.337 (Army Metro). The projectile contains approximately 95% Pb, 2% Sb, 3% Cu, and was designed for terminal ballistic instability. The required accuracy for Gw Pat 90 ammunition out of factory test barrels is 63 mm (0.72 MOA
Minute of arc
A minute of arc, arcminute, or minute of angle , is a unit of angular measurement equal to one sixtieth of one degree. In turn, a second of arc or arcsecond is one sixtieth of one minute of arc....
) for 10 rounds (100% radius measurement method) out to 300 m. The Gw Pat 90 cartridge dimensions are in accordance with the civilian C.I.P. standards for the .223 Remington C.I.P. chambering.
The Gw Pat 90 is used both in the Swiss military and in sport shooting. The very high level of individual training in the Swiss militia (every single soldier bearing a weapon has to shoot for qualification once a year; see Gun politics in Switzerland
Gun politics in Switzerland
Gun politics in Switzerland are unique in Europe. The personal weapon of militia is kept at home as part of the military obligations. Switzerland has one of the highest militia gun ownership rates in the world. In recent times political opposition has expressed a desire for tighter gun regulations...
) and the overall use of the Gw Pat 90 by the many Swiss citizens who shoot in competitions and for amusement has resulted in significant input on its usage. Over 1 billion cartridges have been produced as of 2005.
See also
- 7.62×51mm NATO7.62×51mm NATOThe 7.62×51mm NATO is a rifle cartridge developed in the 1950s as a standard for small arms among NATO countries...
- NATO EPVAT testingNATO EPVAT testingNATO EPVAT testing is one of the three recognized classes of procedures used in the world to control the safety and quality of firearms ammunition....
- Table of pistol and rifle cartridges by yearTable of pistol and rifle cartridges by yearTable of selected handgun, submachine gun, rifle and machine gun cartridges by year....
- List of rifle cartridges
Further reading
- Anthony G. Williams, Assault Rifles and Their Ammunition: History and Prospects, Online Article, October 21, 2006
- Stan Christ, "5.56mm NATO Alternatives", Special Weapons Magazine, Semi-Annual #50 2007, p. 52–59.
External links
- Various photos of 5.56×45mm ammunition
- RUAG Ammotech factsheet on German Army DM11 5.56×45mm ammunition
- RUAG Ammotech factsheet on German Army DM21 5.56×45mm ammunition
- ADI brochure on 5.56mm F1 ball ammunition conforming to the design parameters of the NATO STANAG 4172 and tested with Kistler 6215 transducers at different temperatures
- The AR15.COM Ammo-Oracle
- FAS: 5.56mm Ammunition
- The Gun Zone: 5.56mm FAQ
- The Gun Zone: A 5.56mm Timeline
- I.M.I Small Arms Ammunition Division
- Small Arms
- www.swissmun.ch
- www.swissrifles.com – The New GP 90
- RUAG Ammotec Defence Forces and Government Agencies Ammunitionpage
- RUAG Ammotec Sintox SWISS ORDNANCE cartridge fact sheet
- Swiss Ammunition Enterprise