I truly believe that KaChing is the most deadly form of martial arts I have ever heard of .... OK OK OK ... I'll behave.
KaChing is the sound of a 45 cal pistol being racked to chamber a round. If I am standing approximately ten feet away from anyone who has martial arts training, I can draw, rack a round and fire before that person can get to me. It DOES take a lot of practice to be able to accomplish that however. Unless the martial artist resorts to thrown weapons, a man with a gun ten foot or more away will 99 times out of a hundred be able to draw and fire his weapon before the martial artist can get to him.
By the way, I have had almost two years of Korean Karate from a black belt master ... I grant you that was quite sometime ago, and my muscle memory is almost non-existent now ... but ... I still have most of my speed when it comes to small arms, and my accuracy has always been excellent.