US successfully tests self-steering bullets that can follow moving targets

It is thought to use small fins that shoot out of the bullet and re-direct its path, but the US has not disclosed how it works. It only says that the programme has “developed new approaches and advanced capabilities to improve the range and accuracy of sniper systems beyond the current state of the art”.
Technology in the bullet allows it to compensate for weather and wind, as well as the movement of people it is being fired at, and curve itself in the air as it heads towards its target. That should allow snipers to become much more accurate — even those that are not experienced at using the system, as was found in the tests in February.Those behind the project hope that it can be used to keep troops safe by allowing them to stay further away from the people they’re shooting at, as well as hit them more quickly.
“True to DARPA’s mission, EXACTO has demonstrated what was once thought impossible: the continuous guidance of a small-caliber bullet to target,” said Jerome Dunn, DARPA program manager. “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.
“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 future guided projectiles across all calibers.”

source:  http://www.independent.co.uk/life-style/gadgets-and-tech/news/us-unveils-selfsteering-bullets-that-can-follow-moving-targets-10209985.html