The result was Armalite’s AR-15 rifle, chambered in .223 Remington, propelling a 55-grain bullet at 3,250 fps. Two years after its submission to SAAMI, the U.S. Army adopted Armalite’s AR-15 rifle, ...
The gun is the weapon of choice for many mass ... They don’t hold enough gunpowder to match the velocity of the .223. Any bullet can kill, and instantly, when it hits a vital organ.