Darpa won't say, publicly, how far, how long and how accurate they want the new bullets to be — all that information is classified. But they will say that Exacto should contain a next-gen scope, a guidance system that provides information to direct the projectile, an "actively controlled .50-caliber projectile that uses this information for real-time directional flight control," and a rifle. "Technologies of interest may include: fin-stabilized projectiles, spin-stabilized projectiles, internal and/or external aero-actuation control methods, projectile guidance technologies, tamper proofing, small stable power supplies, and advanced sighting, optical resolution and clarity technologies."

Exacto is one of several projects Darpa is developing to make snipers more accurate and more deadly. The agency has earmarked $7.5 million for a laser-guided bullet program. Darpa gave Lockheed $2 million for advanced sniper scopes that could boost kill rates by tenfold, or more. If the system works out as planned, it would actually allow snipers to remain virtually invisible, lost in the "heat haze" in between them and their targets. Our own David Hambling called the project the "next war's secret weapon."