Double tap A double tap or controlled pair is a shooting technique where two well - aimed shots are fired at the same target with very little time in between shots . Instruction and practice of the double - tap improves overall accuracy as shooters often do not have the gun fully extended on the first shot meaning the second of a double - tap is usually the better . The term hammer is sometimes used to describe a double tap in which the firearm ' s sights are not reacquired by the shooter between shots . Origins . The origin of the double tap technique is credited to William Ewart Fairbairn and Eric Anthony Sykes , British police chiefs in Shanghai during the 1930s to overcome the limitations of full metal jacket ed ( FMJ ) ammunition . FMJ ammunition is commonly used by militaries for feeding reliability , adherence to the Hague Convention regarding non - expanding ammunition , and improved penetration . FMJ rounds can fail to cause sufficient damage , requiring more hits and better shot placement . In Ian Dear ’ s book " Sabotage and Subversion " about British Special Operations Executive ( SOE ) and United States Office of Strategic Services ( OSS ) forces , Fairbairn is reported to have instructed SOE personnel in the double tap from 1944 to 1945 at the SOE training school directed by Fairbairn and Sykes near Arisaig in Scotland . The term " double tap " is now used to describe the broader technique of firing two rounds quickly and accurately to disable an opponent . The tactic is still used today by firearms handlers , police tactical teams , military personnel , counter - terrorist combat units , and other Special Operations Forces personnel . Theory . In the double - tap technique , after the first round is fired , the shooter quickly reacquires the sights for a fast second shot . This skill can be practiced by firing two shots at a time , taking time between the shots to reacquire the sights . With practice , the time between shots grows shorter and shorter until it seems to the observer as if the shooter is just pulling the trigger twice very quickly . There is a natural arc of the front sight post after the round is fired and the recoil kicks in . The soldier lets the barrel go with this arc and immediately brings the front sight post back on target and takes a second shot . The soldier does not fight the recoil . In combat , soldiers shoot until the enemy goes down . For multiple targets , each target should receive a double tap . History . Double taps are an integral part of the " El Presidente " combat pistol shooting drill developed by Jeff Cooper in the 1970s and published in the January / February 1979 issue of " American Handgunner " . Also developed in the 1970s is the Failure Drill or Mozambique Drill , developed by Jeff Cooper student Mike Rousseau . This drill is to practice a situation where a double - tap to the torso fails to stop an attacker and so there ' s a third shot to the head . The term has also been used more recently to refer to the practice of following up a drone missile strike with a second strike several minutes later . In pop culture . Always striking or shooting zombie s with a double tap is one of Columbus ' s rules in the movie " Zombieland . " In the game , SWAT units occasionally shout " Double tap ! Triple tap ! Just keep tapping ! " after the players have taken many hits and still stand .