In the age of precision guided bombs and missiles there has been a projectile that has largely been left behind: the bullet. Sandia National Labs has set off in an attempt to change that. Two Sandia researches who are also hunting buddies, Red Jones and Brian Kast, have worked with their colleagues to create a self-guided bullet. This bullet can be fired from a small caliber, smooth bore rifle and guide itself to a laser-designated target a little over a mile away.
To detect the laser, a small optical sensor sits at the tip of the bullets nose. An 8 bit central processing unit, or CPU, then commands tiny fins through electromagnetic actuators to keep the bullet on course to the target. These fins are protected by a plastic cartridge which drops off as soon as the bullet leaves the rifle’s barrel.
One thing these smart bullets lack when compared to their larger counterparts is an inertial measuring unit. This is because of the bullets much smaller size. Large missiles are slow to make flight path corrections, so the inertial measuring unit is key component in getting the missile on course quickly and staying there. According to Jones, “the natural body frequency of this bullet is about 30 hertz, so we can make corrections 30 times per second. That means we can overcorrect, so we don’t have to be as precise each time.” Not having to have this device makes the bullet lighter and significantly cheaper.
When compared to other bullets a large difference is that many rifles use grooves in the barrels, called rifling, to make the bullet go into a tight spin to make it go straight. It’s the same principle as throwing a football in a tight spiral. The guided bullet uses a smooth bore rifle barrel. This is because “the bullet flies straight due to its aerodynamically stable design, which consists of a center of gravity that sits forward in the projectile and tiny fins that enable it to fly without spin, just as a dart does,” said Jones.
With respect to improved accuracy, computer simulations predict that a conventional bullet can miss a target a half of a mile down range by up to 9.8 yards. In contrast, the Sandia created guided bullet would hit within 8 inches. Additionally, tests have shown that the bullets can reach 2,400 feet per second (Mach 2.1) on conventional gunpowder. The scientists believe that a customized blend of powder will enable the projectile to reach military speeds.
Sandia Labs is currently looking to partner with a commercial company to help manufacture the bullets and bring them to market. Primary customers would be the military and law enforcement as well as recreational shooters.