In the video above, a man shoots open his bottle of beer and then drinks it.
It's extremely awesome, but please, don't try this at home. It's a stunt pulled off by a professional drunk, likely from Denmark, who really enjoys Carlsberg.
The video also doesn't show the aftermath, or give a lesson on what to do when you drink glass shards.
Of course, opening a beer with your shotgun shouldn't be confused with shotgunning a beer. You can try that at home if you're of legal age.