Self-guided bullet could hit laser-marked targets from a mile away: “A group of researchers at Sandia National Laboratories have built a prototype of a small-caliber bullet capable of steering itself towards a laser-marked target located approximately 2,000 meters (1.2 miles) away. The dart-like design has passed the initial testing stage… The four-inch (10 cm) long projectile is to be used with smoothbore arms, meaning ones with non-rifled barrels. Rifling involves cutting helical grooves in the barrel to give the bullet a spin that, thanks to the gyroscopic effect, improves its aerodynamic stability and accuracy. In a self-guided projectile, however, such spinning movement would prevent the bullet from reliably turning towards the target when in flight. For this reason, the group of researchers lead by Red Jones and Brian Kast decided to use a dart-like design that includes tiny fins to allow the projectile to fly straight, without a spin.” (via Gizmag).