Actually the most important point that needs to be made is that this soldier has obviously been to the Imperial Stormtrooper school of sharpshooting.
He's shooting at the printer from about 30 feet away and still manages to hit the barrel its sitting on more often than the printer!
It's just the American style of shooting; throw enought bullets at it and you're bound to hit something. 
nah, hes just trying to hit it with a gun thats supposed to be mounted on a little stand when deployed.
see! all those hours playing Joint Ops werent for nothing after all!