A shooter, carrying a concealed firearm, faces downrange approximately five yards from a paper target. For safety reasons, do not use any concealed-carry holster that allows the gun to be pointed in the direction of anyone on the range.
A second person stands back to back with the shooter. He or she will act as the deadly force assailant.
A third person, preferably a range safety officer, stands to the side of the shooter and deadly force assailant holding a shot timer.
On the sound of the shot timer, the shooter draw his firearm from concealment while, at the same time, the deadly force assailant runs away from the shooter.
The deadly force assailant stops running at the sound of the first shot.
The physical conditioning of the attacker.
The amount of time it takes to recognize a threat and respond. This typically takes anywhere from 1.5 to 3 seconds.
Ambient light. Low light will slow response times due to difficulty to identify a threat.
The location of the firearm on the shooter's body, and shooter's familiarity with drawing from that position.
Familiarity, or lack of familiarity with the concealed firearm and holster, will also impact time and distance. Be sure to become proficient with external safeties, clearing malfunctions, magazine releases, and holster retentions before carrying any gun in any holster.