When I read the title of the post, that particular "Callahan" moment is exactly what came to mind.Mine has to be without a doubt:
“I know what you're thinking. Did he fire six shots or only five? Well, to tell you the truth, in all this excitement, I've kinda lost track myself. But being as this is a .44 magnum, the most powerful handgun in the world, and would blow your head clean off, you've got to ask yourself one question: "Do I feel lucky?" Well, do ya, punk?”
Inspector Harold Francis Callahan is my winner for coolest gun moment ever!!!