The Defense Advanced Research Projects Agency (DARPA) of the Department of Defense is moving forward with its goal to develop a self-steering bullet that can change its direction in mid-air to hit a moving target.

DARPA has released a new video demonstrating the accuracy of the Extreme Accuracy Tasked Ordnance (EXACTO) bullet, a 0.50-caliber round equipped with the ability to keep its target well within its sights and hit it right on the mark all the time. The bullet is being developed by Thousand Oaks, California-based Teledyne Scientific and Imaging in a project funded by DARPA.

The video shows the EXACTO bullet used in a live-fire test where expert snipers trained in the use of the special bullet hit a moving target during all of the seven tries. It also shows a novice marksman accurately hitting a moving target using the EXACTO bullet.

"True to DARPA's mission, EXACTO has demonstrated what was once thought impossible: the continuous guidance of a small-caliber bullet to target," says Jerome Dunn, DARPA program manager, in a statement. "This live-fire demonstration from a standard rifle showed that EXACTO is able to hit moving and evading targets with extreme accuracy at sniper ranges unachievable with traditional rounds."

DARPA does not provide details of how the bullet keeps track of its target. However, it does say that the .50-caliber bullet, about the size of a Sharpie marker, is equipped with a guidance system that allows it to track it's target's location at all times and change its course if that target moves. DARPA also says that EXACTO takes into consideration changeable factors such as wind movement, weather, and the target's movement.

One of DARPA's biggest challenges was fitting the entire guidance system into such a small package, making the feat of cramming it all into a .50-caliber bullet a milestone in itself.

"Fitting EXACTO's guidance capabilities into a small .50-caliber size is a major breakthrough and opens the door to what could be possible in the future," Dunn says.

Such an extremely accurate bullet is useful for soldiers in combat by providing increased sniper effectiveness, especially in conditions marked by high winds or dusty terrains. EXACTO also offers better safety for troops by allowing a greater shooter standoff range and less time engaging with targets.