He ordered a number of them to replace M2 carbines that were in use by the Air Force. At a 4th of July picnic, Air Force General Curtis LeMay fired an AR-15 and was very impressed with it. In May of that year, a report was produced stating that five- to seven-man squads armed with AR-15 rifles had higher hit probabilities than 11-man squads armed with M-14 rifles. 222 caliber cartridges being developed for the SCHV project, the 222 Special was renamed. ĭuring parallel testing of the T44E4 (future M14) and the AR-15 in 1958, the T44E4 experienced 16 failures per 1,000 rounds fired compared to 6.1 for the AR-15. Remington created a larger cartridge called the '.222 Special', which was loaded with DuPont IMR4475 powder. Stoner contacted both Winchester and Remington about increasing the case capacity. But testing showed chamber pressures to be excessively high. During a public demonstration the round successfully penetrated the U.S. Testing was done with a Remington 722 rifle with a 22-inch Apex barrel. He used DuPont IMR4198, IMR3031, and an Olin powder to work up loads. Robert Hutton (technical editor of Guns & Ammo magazine) started development of a powder load to reach the 3,300 ft/s (1,006 m/s) goal. Using a ballistic calculator, they determined that a 55-grain bullet would have to be fired at 3,300 ft/s (1,006 m/s) to achieve the 500-yard performance necessary. Stoner and Sierra Bullet's Frank Snow began work on the. As a result, CONARC ordered rifles to test. In May 1957 Stoner gave a live-fire demonstration of the prototype of the AR-15 for General Willard G. Harvey was ordered to cease all work on the SCHV to avoid any competition of resources.Įugene Stoner of Armalite (a division of Fairchild Industries) had been advised to produce a scaled-down version of the 7.62mm AR-10 design. Concurrently with the SCHV project, Springfield Armory was developing a 7.62mm rifle. 222 Remington cartridge case to meet the requirements. Springfield Armory's Earle Harvey lengthened the. Accuracy and ballistics equal to M2 ball ammunition (.Penetration of US steel helmet through one side at 500 yards.Select fire for both semi-automatic and fully automatic use.Bullet exceeding supersonic speed at 500 yards.Concerns about the recoil and overall effectiveness of 7.62 mm were overruled by the US, and the other NATO nations accepted that standardization was more important than selection of a cartridge that was otherwise ideal. 280 round, including developing a version of the FN FAL in. The FN company had also been involved in the development of the. 280 (7 mm) cartridge when the selection of 7.62×51mm (.300) as the NATO standard was made. The British had extensive evidence through their own experimentation with intermediate cartridges since 1945 and were on the point of adopting the. At the time of selection there had been criticism that the recoil power of the 7.62×51mm NATO, when fired from a handheld lightweight modern service rifle, did not allow a sufficient automatic rate of fire for modern combat. In 1954, the larger 7.62×51mm NATO rifle cartridge was selected as the first standard NATO rifle cartridge. The 7.62×51mm NATO and 5.56×45mm NATO cartridges compared to an AA battery 223 Remington cartridge designed by Remington Arms in the early 1960s. Though they are not entirely identical, the 5.56×45mm NATO cartridge family was derived from and is dimensionally similar to the. 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. It consists of the SS109, L110, and SS111 cartridges. The 5.56×45mm NATO (official NATO nomenclature 5.56 NATO, but often pronounced 'five-five-six') is a rimless bottlenecked intermediate cartridge family developed in the late 1970s in Belgium by FN Herstal. Source(s): NATO EPVAT testing, QuickLOAD, SAAMI, C.I.P.

NATO, Japan, South Korea, Taiwan, Australia, other major non-NATO allies 5.56×45mm NATO with measurement, left to right: projectile, empty case, complete round with projectile in case

Sky force reloaded trainer 5.56