Dan Bilzerian begged cops to hand him a gun as the Las Vegas shooter sprayed bullets at concertgoers ... and it resulted in a heated confrontation.
Dan -- who flaunts his arsenal of weapons -- has been skewered on social media for running from the massacre. That's why this video is so interesting ... Dan actually wants to join forces to take down the murderer, but cops weren't having it.
Listen closely ... Dan asks a heavily armed Vegas cop for one of his guns, and the cop recoils ... he seems insulted that some random guy would dare ask him for a weapon.
Dan pulls out his wallet, appearing to show cops he has the right to pack heat, and screams, "Give me a gun!" The cop fires back, "No, get the f*** away from me right now."