In the quest in minimizing collateral damage, especially in terms of civilian casualties, three researchers at the U.S. Army Armament Research, Development and Engineering Center were awarded a patent for the concept of patent a limited range, self-destructing projectile.  The patent was filed on the 7th of May 2013 and was eventually approved last September 1, 2015 according to Army.mil.

The concept of the limited range projectile states that it will have pyrotechnics built in the bullet. When fired, the bullets explode after a short period of time, stopping to bullet in its flight. The pyro built in is immediately ignited when fired, just like the concept of fireworks and will ignite the reactive material after achieving a curtained determined range and will render the bullet “into an aerodynamically unstable object.”

U.S. Patent 9,121,679 B1, "Limited Range Projectile"

This means that civilian bystanders standing further away from the actual target will potentially not get hit by the bullet, and that means lesser civilian casualties especially in built-up areas such as urban centers. A stray bullet or a missed shot can spell life and death those who are not the intended recipients of the bullet.

According to Stephen McFarlane, one of the researchers, "The biggest advantage is reduced risk of collateral damage." He also added that, "In today's urban environments others could become significantly hurt or killed, especially by a round the size of a .50 caliber, if it goes too far."

So with the patent, will the project go forward? Unfortunately, it may not for the meantime as funding for the project has dried up. But McFarlane is unfazed, "This was the first patent we applied for that has been approved. That in itself is an accomplishment." They hope that the project will be revived when more technology is needed by soldiers to make them more effective in the battlefield with less collateral damage.