Here's a frustrated Dallas Cowboys fan shooting his 55-inch TV to death after the Cowboys lost to the Arizona Cardinals on Monday ... and it's pretty crazy.

The fan lost his mind once he realized the Cowboys were moving to 2-4 after a pretty awful performance against AZ.

So, he threw his beer at the TV, threw a couple of punches ... and then whipped out a .380 handgun and opened fire.

After the murder, the fan took a breath -- and poured out some beer to mourn the loss of his TV.

The Cowboys, however, are still very much alive in the playoff race -- they're in 1st place in the NFC East, the worst division in football.

Next up for Dallas ... they take on the Washington Football Team on Sunday. Washington also has a terrible record -- 1-5.