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5. 56x45mm NATO

U. S. Military 5. 56 mm cartridges
Type Rifle
Place of origin Flag of the United States United States
Service history
Used by NATO
Production history
Designer Remington Arms
Specifications
Parent case .223 Remington
Case type Rimless, bottleneck
Bullet diameter 5. A rifle is a Firearm designed to be fired from the shoulder with a barrel that has a helical groove or pattern of grooves ("rifling" cut into the barrel walls The United States of America —commonly referred to as the The North Atlantic Treaty Remington Arms is a major American manufacturer of Rifles Shotguns other Firearms, Revolvers and Ammunition. A cartridge (also known as a "round" packages the Bullet, Gunpowder and primer into a single metallic case precisely made to fit the A bullet is a solid Projectile propelled by a Firearm or Air gun and is normally made from metal (usually Lead) 69 mm (0. 224 in)
Neck diameter 6. 43 mm (0. 253 in)
Shoulder diameter 8. 99 mm (0. 354 in)
Base diameter 9. 55 mm (0. 376 in)
Rim diameter 9. 6 mm (0. 38 in)
Rim thickness 1. 14 mm (0. 045 in)
Case length 44. 7 mm (1. 76 in)
Overall length 57. 4 mm (2. 26 in)
Rifling twist 1:178 mm or 1:229 mm (7" or 9")
Primer type Small rifle
Ballistic performance
Bullet weight/type Velocity Energy
62 gr (4. Rifling refers to the Helix -shaped pattern in the barrel of a Firearm, which imparts a spin to a Projectile around its long axis The percussion cap, introduced around 1830, was the crucial invention that enabled muzzle-loading firearms to fire reliably in any weather In many cultures a grain is a unit of measurement of Mass that is based upon the mass of a single seed of a typical Cereal. 0 g) FMJBT 940 m/s (3,100 ft/s) 1,775 J (1,309 ft·lbf)

5. For other uses of the words gram or gramme see Gram (disambiguation. The foot per second (plural feet per second) is a unit of both Speed (scalar and Velocity (vector quantity which includes direction The joule (written in lower case ˈdʒuːl or /ˈdʒaʊl/ (symbol J) is the SI unit of Energy measuring heat, Electricity The foot-pound force, or simply foot-pound (symbol ft·lbf or ft·lb) is a unit of work or Energy (a scalar 56x45mm NATO, standardized under STANAG 4172, is a rifle cartridge. STANAG is the NATO abbreviation for Standardization Agreement, which set up processes procedures terms and conditions for common Military or technical A rifle is a Firearm designed to be fired from the shoulder with a barrel that has a helical groove or pattern of grooves ("rifling" cut into the barrel walls A cartridge (also known as a "round" packages the Bullet, Gunpowder and primer into a single metallic case precisely made to fit the It is a standard cartridge for NATO forces, and for several nations not part of NATO. The North Atlantic Treaty It is derived from, but not entirely interchangeable with, the .223 Remington cartridge. This is due to, among other things, the greater gas pressure of the 5. 56 mm military round.

Contents

History

The previous standard NATO rifle round was the 7.62x51mm NATO, derived from the .308 Winchester rifle cartridge and designed to replace the U. The 762x51mm NATO is a Rifle cartridge developed in the 1950s as a standard firearm cartridge among NATO countries S. military's .30-06 Springfield rifle cartridge. At the time of selection, there had been criticism that the 7. 62 mm round was too powerful for modern service rifles, causing excessive recoil, and that the weight of the ammunition did not allow for enough "firepower" in modern combat. The service rifle (also known as standard-issue rifle) of a given Army or Armed force is that which it issues as standard to its Soldiers In A soldier can carry nearly twice as much 5. 56 mm ammunition as 7. 62 mm for the same weight.

During the late 1950s, ArmaLite and other U. ArmaLite, originally the ArmaLite Division of the Fairchild Engine and Airplane Corporation, is a Small arms manufacturing company S. firearm designers started their individual Small Caliber/High Velocity (SCHV) assault rifle experiments using the commercial .222 Remington cartridge. A firearm is a Tool that projects either single or multiple Projectiles at high velocity through a controlled explosion 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 . This is an article about the US Government Arsenal For the contemporary commercial manufacturer see Springfield Armory Inc 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 . AR-15 (for Ar malite model 15, often mistaken for A utomatic R ifle is the common name for the widely-owned semi-automatic M16 (more formally United States Rifle II Caliber 556 mm M16) is the U 223 Remington was standardized as the 5. 56x45mm. However, the . 223 Remington was not introduced as a commercial sporting cartridge until 1964.

The British had extensive evidence with their own experiments into an "intermediate" round since 1945 and were on the point of introducing a .280 inch (7 mm) round when the selection of the 7. 62 mm round was made. The FN company had also been involved. Fabrique Nationale de Herstal, more often abbreviated as Fabrique Nationale or simply FN, is a Belgian manufacturer of Firearms The official 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 round. However the concerns would prove to be valid and led to the development of the 5. 56 cartridge.

During the 1970s, NATO members signed an agreement to select a second, smaller caliber cartridge to replace the 7. 62 mm NATO. Of the cartridges tendered, the 5. 56 mm was successful, but not the 5. 56 mm loading (M193 Ball) as used by the U. S. at that time. Instead, the Belgian FN SS109 loading was chosen for standardization. Fabrique Nationale de Herstal, more often abbreviated as Fabrique Nationale or simply FN, is a Belgian manufacturer of Firearms The official The SS109 used a heavier bullet at 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 m. Some believe that this requirement has made the M855 less capable of fragmentation than the M193 as discussed below.

Performance

From left to right: 9x19mm Parabellum, .40 S&W, .45 ACP, 5.7x28mm, 5.56x45mm, .300 Winchester Magnum, and two shotgun shells; 2.75-inch and 3-inch 12 gauge.
From left to right: 9x19mm Parabellum, .40 S&W, .45 ACP, 5.7x28mm, 5. The 9x19mm Parabellum is a pistol cartridge introduced in 1902 by the German weapons manufacturer Deutsche Waffen und Munitionsfabriken (DWM for their The 57x28 mm cartridge is a small caliber cartridge for Pistols Submachine guns Personal defense weapons and Carbines developed by 56x45mm, .300 Winchester Magnum, and two shotgun shells; 2. A shotgun shell (shotshell is a self-contained cartridge loaded with shot or a slug designed to be fired from a Shotgun. 75-inch and 3-inch 12 gauge. The Gauge or bore of a Shotgun or Rifle is a unit of measurement used to express the Diameter of the barrel.
5.56x45mm NATO rounds in a STANAG magazine.
5. 56x45mm NATO rounds in a STANAG magazine.

The 5. 56x45mm NATO cartridge with the standard military ball bullet (NATO: SS109; U. A full metal jacket (or FMJ) is a Bullet encased in a shell of Copper Alloy (such as Gilding metal or Cupronickel) or a S. : M855) will penetrate approximately 15 to 20 inches (38 to 50 cm) into soft tissue in ideal circumstances. As with all spitzer shaped projectiles it is prone to yaw in soft tissue. A spitzer is an aerodynamic bullet design used in most intermediate and high-powered rifle cartridges However, at impact velocities above roughly 2,700 ft/s (820 m/s), it may yaw and then fragment at the cannelure (the groove around the cylinder of the bullet). Flight dynamics is the science of air and space vehicle orientation and control in three dimensions These fragments can disperse through flesh and bone, inflicting additional internal injuries. [1] Fragmentation, if and when it occurs, seems to impart much greater damage to tissue than bullet dimensions and velocities would suggest. This fragmentation effect is highly dependent on velocity, and therefore barrel length: short-barreled rifles generate less muzzle velocity and therefore rounds lose effectiveness at much shorter ranges than longer-barreled rifles. For the fictional characters see Gunbarrel (Transformers. A gun barrel is the tube usually Metal, through which a controlled Explosion A gun's muzzle velocity is the speed at which the Projectile leaves the muzzle of the gun There has been much criticism of the poor performance of the round, especially the first-round kill rate when using firearms that don't achieve the velocity to cause fragmentation. This typically becomes an issue at longer ranges (over 100 m) or when penetrating heavy clothing, but this problem is compounded in shorter-barreled weapons. The 14. 5-inch (37 cm) barrel of the U. S. military's M4 Carbine can be particularly prone to this problem. At short ranges, the round is reported to be mostly effective, and its tendency to fragment reduces the risk of "overpenetration" when used at close range. However, if the round is moving too slowly to reliably fragment on impact, the wound size and potential to incapacitate a target 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 Grendel and the 6.8 SPC. The 65 mm Grendel (or 65x39mm Grendel is a 65 mm caliber intermediate cartridge developed in 2002 by Bill Alexander of Alexander Arms and Arne Brennan of Competition Shooting The 68 mm Remington SPC (or 68x43mm is a new Rifle cartridge that was developed with collaboration from individual members of US SOCOM.

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 Mk 262 (Mark 262 is a match quality 556x45mm NATO round manufactured by Black Hills Ammunition made originally for the Special Purpose Rifle (SPR 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 round to fire from their M4A1 carbines. The United States Navy Mark 12 Mod 0/1 Special Purpose Rifle ( SPR) is a Rifle in service with United States special forces in Operation Enduring Freedom

5. 56 mm NATO versus . 223 Remington

While the 5. 56 mm and . 223 cartridges are very similar, they are not identical. Military cases are generally made from thicker brass than commercial cases; this reduces the powder capacity (an important consideration for handloaders[1]), and the NATO specification allows a higher chamber pressure. Handloading or reloading is the process of loading Firearm cartridges or shotgun shells by assembling the individual components (case/shotshell Test barrels made for 5. 56 mm NATO measure chamber pressure at a the case mouth, as opposed to the SAAMI location. This difference accounts for upwards of 20,000 psi (140 MPa) difference in pressure measurements. That means that advertised pressure of 58,000 psi (400 MPa) for 5. 56 mm NATO, is around 78,000 psi (540 MPa) tested in . 223 Rem test barrels. The 5. 56 mm chambering, known as a NATO or mil-spec chambers, have 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 chambering, known as SAAMI chamber, is allowed to have a shorter leade, and is only required to be proof tested to the lower SAAMI chamber pressure. The American Sporting Arms and Ammunition Manufacturers' Institute (commonly abbreviated as SAAMI and pronounced "Sammy" is an association of American A proof test is a test wherein a deliberately overpressured round is fired from a Firearm in order to verify that the firearm is not defective and will not explode To address these issues, various proprietary chambers exist, such as the Wylde chamber (Rock River Arms)[2] or the Armalite chamber, which are designed to handle both 5. ArmaLite, originally the ArmaLite Division of the Fairchild Engine and Airplane Corporation, is a Small arms manufacturing company 56 mm and . 223 equally well.

Using commercial . 223 cartridges in a 5. 56-chambered rifle should work reliably, but generally will not be as accurate as when fired from a . 223-chambered gun due to the longer leade. [3] Using 5. 56 mil-spec cartridges (such as the M855) in a . 223-chambered rifle can lead to excessive wear and stress on the rifle and even be unsafe, and the SAAMI recommends against the practice. [4] Some commercial rifles marked as ". 223 Remington" are in fact suited for 5. 56 mm, such as many commercial AR-15 variants and the Ruger Mini-14, 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. The Mini-14, Mini-30, and Mini-68 are small lightweight semi-automatic Carbines manufactured by the U 56 mm ammunition. [5]

Comparison of 5. 56 mm versus 7. 62 mm NATO

Round Cartridge size Bullet weight Velocity Energy
5. 56 mm NATO 5. 56x45mm 3. 95–5. 18 g 772–930 m/s (2526–3051 ft/s) 1,700–1,830 J
7. 62 mm NATO 7. 62x51mm 9. 33 g 838 m/s (2749 ft/s) 3,275 J

The NATO Ball round (U. S. : M855) can penetrate up to 3 mm (about 1/8") of steel at 600 meters[2]. According to Nammo, a Norwegian ammunition producer, the M995 can penetrate up to 12 mm (nearly 1/2") of RHA steel at 100 meters. [3]

Military cartridge types

M855 and M856 rounds in an ammunition belt using M27 disintegrating links.
M855 and M856 rounds in an ammunition belt using M27 disintegrating links.

Use

Main article: List of 5.56x45mm NATO firearms

See also

Notes

  1. ^ Accurate Powder Co. Many nations (both NATO and non-NATO members use the 556 mm NATO cartridge in their Rifles Examples include Australian F88 Austeyr assault The Gewehr Patrone 90 or "Rifle Cartridge 90" is the standard round used by the Swiss military in its assault rifle the SIG SG 550. The 762x51mm NATO is a Rifle cartridge developed in the 1950s as a standard firearm cartridge among NATO countries 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. Table of selected pistol sub-machine gun rifle and machine gun cartridges by year List of Rifle cartridges, by category and then by name Rimfire. . .223 Remington handloading data.
  2. ^ Rock River Arms
  3. ^ Winchester
  4. ^ The Gun Zone
  5. ^ Armalite

Sources and external links

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