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As firearm manufacturers began development on the assault rifle, there became an increasing need for a small caliber, high velocity round. ArmaLite began experimenting with the .222 Remington cartridge but soon found there was not enough powder capacity to meet the needs to the market. ArmaLite reached out to Remington to develop a similar cartridge with a longer case body and shorter neck which later became known as the .222 Remington Special. As more competitors developed similar cartridges, the .222 Remington Special became known as the .223 Remington. Once the US military adopted the ArmaLite M16 in 1963, the .223 Remington was standardized as the 5.56x45mm NATO.


5.56 ammo uses standard 62 gr. Steel core bullets that penetrate 15-20 in. into soft tissue. At high velocities 5.56 ammo may yaw and then fragment through flesh and bone causing extreme internal injuries.

Modern Advances

The US Military has adopted an alternative 5.56 ammo with a 77-grain bullet classified as the MK 262. The heavy, but lightly constructed bullet fragments more at a shorter range, yet will still fragment from longer ranges. It was originally designed for use in the MK 12 SPR and is a favorite with special forces units that were seeking a more effective cartridge for use in their M4A1 carbines. 5.56 ammo can be found in different varieties including tracer, ball, grenade, practice, long range special ball, and dummy variations. sellers update their auction listings frequently, so if you’re looking to buy a 5.56 ammo, check back often.


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