OK. Here is the youtube link.
Guy drawing from concealment; 6 rounds on target (7 yrds) in 1.98 seconds.
Bill Drill
Bear in mind - in the OP's scenario, you are acting. The bad guy would be reacting. Those of you who don't shoot a LOT, but do shoot enough to know, will realize how easy it is to pull that first shot way off target, especially with a DA revolver or long DA first shot from a DA/SA semi.
I have not been in combat and realize that no one but those who have really know what they'd do. But thinking things through ahead of time AND a lot of practice on the fundamentals gives you a better chance if things hit the fan.