The 5.56×45mm NATO (official NATO nomenclature 5.56 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.[2] It is derived from, but not identical to, the .223 Remington cartridge. When the bullet impacts at high velocity and yaws[3] in tissue, fragmentation creates a rapid transfer of energy which can result in dramatic wounding effects.[4][5][6]
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 lead.[29] 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.[30][31] Some commercial rifles marked as '.223 Remington' are in fact suited for 5.56 mm NATO, such as many commercial AR-15 variants and theRuger 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.[32]
Many nations (both NATO and non-NATO members) use the 5.56 mm NATO cartridgein their rifles. Examples include:
Argentina FARA 83Australian F88 Austeyr assault rifle and F89 Minimi machine gun. (ADI Thales also supplies ammunition)Austrian Steyr AUG and the Steyr ACR (Flechette) assault rifleBelgium: CAL, Minimi, FNC, SCAR, F2000.Bulgaria: Arsenal AD AR seriesBrazil: IMBEL MD2, LAPA FA-03Chinese QBZ-97, QBZ-03, CQ 5.56, QBB-97, KBU-97ACanadian Colt Canada C7 rifle, C8 rifle and the C9Croatia: HS Produkt VHS Assault rifle (VHS-K (short version) and VHS-D (long version))Czech Republic: CZ-805 BRENFrench: FAMASGeorgian: G5 carbineGermany: HK33,HK53, HK13E, HK23E, G41, G36, MG4, HK416, RH-70Indian INSAS assault rifleIndonesian PINDAD SS1 and SS2 assault riflesIranian Khaybar KH2002Israeli IMI Negev, IMI Galil assault rifle and Tavor TAR-21bullpup assault rifleItalian AR70/90, Franchi mod. 641, SOCIMI AR-831Japanese Howa Type 89MalaysianVB Berapi LP06 assault rifleMexican FX-05 Xiuhcoatl assault riflePeruvian FAD assault rifle, Diseños Casanave SC-2005Philippine MSSR sniper rifle and Special Operations Assault Rifle (SOAR).Polish Kbk wz. 1996 Mini-Beryl and Beryl wz.96 assault riflesRussian AK-101, AK-102, AK-108, AK-12 and KBP A-91Serbian M85/M90 andM21Singaporean SR-88 and SAR-21 assault rifles and Ultimax 100 machine gunSouth African Vektor R4 series of rifles and carbines, Truvelo Raptor, Vektor CR-21assault rifle and Mini-SS machine gunSouth Korean K1, K2 assault rifles, and K3 machine gunSwedish Ak 5 system, derived from the Belgian FN FNC assault rifleSwiss SIG 530/540/550 series, with lesser performances than the round for which it was initially designed, the Gw Pat.90 cartridgeTaiwan: T65 Assault Rifle, T86 assault rifle and T91 Assault Rifle.Thailand: Rung Paisarn RPS-001Turkish Safir T-15 and Safir T-17United Kingdom:Sterling SAR-87, SA80 series rifles.US M16 rifle series, M4 Carbine, US/German HK-416, US/Belgian M249 Squad Automatic Weapon, and US/Belgian Mk. 16 SCAR-L
Examples of rifles marketed for non-military applications that can take the 5.56 cartridge include:
Bushmaster_ACR assault rifleKel-Tec SU-16 series semi-automatic riflesSaiga 223 semi-automatic rifleRemington Model 7615 Police Patrol RifleRemington Model 700 series bolt-action rifleRuger Mini-14 semi-automatic rifleSteyr Scout series bolt-action rifleWinchester Model 70 series bolt-action rifleVolquartsen Evolution autoloading competition/varmint rifleSmith & Wesson M&P15 semi automatic ar-15 rifleBushmaster_Firearms_International#Carbon_15 semi automatic carbon polymer based ar-15 rifle
My unit – B Company, 2nd Battalion, 504th Parachute Infantry Regiment – was deployed to Afghanistan from April 2005 to March 2006. While there, we were attached to Special Forces at Camp Tillman on the Afghan border…. I saw first-hand what happens when your weapon jams up because of the harsh environments we have to call home there. An 18B weapons sergeant was shot in the face due directly to his weapon jamming. I just can’t believe that after things like this happen, the Army is still buying more M4s.