First of all the magazine capacity blows since all the bullets are lined up in the barrel, second the accurancy would blow since the more a bullet travels in the barrel the more acurate it will be, since the first bullets practically dont trave at all in the barrel they would be as inacurate as as hell.
Also i didnt see any kind of option to stop the shooting i mean, you have ur gun, and BAM... 1 milisecond and you fired all your bullets at one single point? thats not very useful