The gun kata made for some very effective and well-choreographed fight scenes in the movie, bringing hand-to-hand style to ranged-weapon combat. However, a fighter attempting to employ such a system in real life would be unlikely to survive very long.
Developed through analysis of thousands of recorded gun fights, it was determined that the geometric distribution of antagonists in any gun battle is a statistically predictable element.
The Gun Kata treats the gun as a total weapon. Each new position representing a maximum kill zone, inflicting maximum damage on the maximum number of opponents, while keeping the defendant clear of the statistically traditional trajectories of return fire.
Supposedly developed by analysis of thousands of gunfights, which apparently developed into the idea that it is statistically possibile to determine where any individual is located and where all shots will be delivered from in any particular gunfight.
General practicioners of this martial art are "Grammaton Clerics" in the film "Equilibrium," who are drilled in the "katas" (routines practiced and memorized by rote) in order to use their firearms as an extension of the self.
While visually appealing, Gun Kata has very little real world application as it discounts enemies that attack from the prone position or from ranged attackers (such as snipers).
DuPont: "The gunkatas. Through analysis of thousands of recorded gunfights, the Cleric has determined that the geometric distribution of antagonists in any gun battle is a statistically predictable element. The gunkata treats the gun as a total weapon, each fluid position representing a maximum kill zone, inflicting maximum damage on the maximum number of opponents while keeping the defender clear of the statistically traditional trajectories of return fire. By the rote mastery of this art, your firing efficiency will rise by no less than 120%. The difference of a 63% increase to lethal proficiency makes the master of the gunkatas an adversary not to be taken lightly."