Defense Advanced Research Projects Agency (DARPA) in the US is currently involved in a project to develop technology to revolutionize rifle accuracy and range with the ultimate goal of improving sniper effectiveness and increasing troop safety. The first technology that they have generated from this project is self-guiding bullets that can change course mid-flight. The new bullets are called "Extreme Accuracy Tasked Ordinance" (EXACTO). These bullets function in a similar way to laser-guided bombs. Currently, the system uses .50 caliber EXACTO bullets that have real-time guidance systems that allow the bullet to correct their course to the target. The systems use optical sensors placed on the surface of the nose that send data to internal systems that use it to adjust the position of a series of external fins that are what change the bullets direction.
DARPA's Extreme Accuracy Tasked Ordnance (EXACTO) program recently conducted the first successful live-fire tests demonstrating in-flight guidance of .50-caliber bullets. This video shows EXACTO rounds maneuvering in flight to hit targets that are offset from where the sniper rifle is initially aimed. EXACTO's specially designed ammunition and real-time optical guidance system help track and direct projectiles to their targets by compensating for weather, wind, target movement and other factors that could impede successful aim.
