I saw this movie (or TV movie) in early-mid 90s, on my local TV channel. I think it was made in late 80s. It was definetely US made, and it was action film. Main hero was white average looking man. He was probably Viatnam war veteran/or homeless (like Rambo). His buddy was tall white heavily build (fat) bearded man who was also illegal gun runner. The key point that I remember that the fat man had minivan with minigun (GE M134 gatling machinegun) concealed inside, and he nicknamed this minigun as “weapon of mass destruction”. Main hero wanted to borrow the van, but the fat man initially refused. But in the end he helped, using the minigun to gun down large amounts of criminals (?).