What do you do if your pistol doesn't go "Bang!" when you need it to in the middle of a string of fire?
If you hear a "click" when you expect a "bang," pull the gun in, tap the magazine to make sure it's properly seated, rotate your hand up and over the top of the slide, making sure that you're behind the ejection port, and rack the slide vigorously.
Drive back out and engage the threat.
"Tap and Rack" is your immediate response to pulling the trigger and not having it go bang.
[Because, you have to trust bald guys with beards...]