Research begun by the U.S. Army in 1948 determined that the most desirable infantry small arms should be a weapon utilizing a high velocity 22 caliber bullet. Testing and evaluations conducted between 1950-1957 of various 22 caliber high-velocity infantry rifles led to the development of the AR-15 prototype rifle in 1957, along with the newly developed 22 caliber .223 Remington cartridge (5.56x45mm). The AR-15 would eventually evolve into the original U.S. Military M16 rifle in 1963, while the .223 Remington cartridge was redesignated as the "5.56 mm Ball, M193" cartridge and was adopted, along with the M16 and it's variants, as the official rifle system of the U.S. Armed Services. During the late 1970's, in response to continuing military small arms development, the cartridge was modified, to become the NATO Standard "5.56 mm Ball Cartridge M855" that is still in use today in a variety of military small arms, including the updated US Military M16A2/A3/A4 and M4 Carbine models. .
This model depicts the early M193 and newer M855 cartridge, which can be identified by its painted green tip. Also shown are three M16 cartridge magazines: an original 20 round pre1963 steele "waffle" design, a 20 round aluminum mid 1960's design, and a 30 round aluminum design introduced in 1969. The magazines are modified models downloaded from the internet, while the cartridges are modified versions of RL Gun's original model. #223 #223_Remington #22_caliber #556 #556_NATO #556x45 #ammo #ammunition #Armalite #Armed_Services #Arms #Army #bullet #cartridge #Colt #gun #M16 #NATO #rifle #round #US #US_Army #weapon