Well sci-fi is now reality.
The US Army is fielding a new weapon in Afghanistan called the XM-25 which can have its munitions programmed to hit a target behind walls.
Crouching behind his own cover, a U.S. soldier armed with the XM-25 can point his weapon at the wall behind which the enemy is hiding to get the precise distance. The rounds, which come four to a magazine plus one in the chamber, can then be programmed to travel just a short distance behind that to explode precisely where the insurgent is believed to be hiding.
With the scope aimed at the top of the wall, the round will fire and explode before impact, at the precise location programmed by the soldier, raining a hail of explosives and fragments on to the enemy.
It all takes mere seconds -- five to program and fire, two for travel.
The rounds also take into account air pressure and temperature to accurately hit their marks.