A small-caliber, self-guided bullet is under development at Sandia National Laboratories. Smooth-bore firearms could hit laser-designated targets at distances of up to 2K meters.
(Self-Guided Bullet Accurate Over One Mile video)
Sandia’s design for the four-inch-long bullet includes an optical sensor in the nose to detect a laser beam on a target. The sensor sends information to guidance and control electronics that use an algorithm in an eight-bit central processing unit to command electromagnetic actuators. These actuators steer tiny fins that guide the bullet to the target...
Computer simulations showed an unguided bullet under real-world conditions could miss a target more than a half mile away (1,000 meters away) by 9.8 yards (9 meters), but a guided bullet would get within 8 inches (0.2 meters), according to the patent.
Plastic sabots provide a gas seal in the cartridge and protect the delicate fins until they drop off after the bullet emerges from the firearm’s barrel.
We're getting closer to smart bullets, five-inch fire-and-forget self-tracking bullet-missiles like in Michael Crichton's 1984 movie Runaway.