Katt Williams -- Alleged Victims Say Katt Committed Vicious Gun Attack

Katt Williams is a gun-toting lunatic who smashed a car window with the butt of the gun and then had the nerve to defame the alleged victims ... this according to the alleged victims

TMZ broke the story ... L.A. County Sheriff's deputies rushed to The Comedy Store in West Hollywood Tuesday after Katt allegedly pulled a gun on someone. Katt told us the story was BS ... saying he was threatened by gangbangers who then called cops to get him in trouble.

But the 4 alleged victims tell us ... they have nothing to do with gangs. They were outside the club shooting a documentary, "From the Hood to Hollywood."

They say they spotted Katt and asked if they could shoot him for the doc, but he angrily said no. They claim a woman then pulled up, popped the trunk, Katt went inside and pulled out 2 big guns ... then walked over to their car and smashed in the window with the butt of one of the guns.

The guy who was driving says the glass shattered and he suffered cuts.

The 4 filmmakers say Katt can expect a lawsuit.

As for Katt, he tells us, "Whatever the gangbangers say."