User blog comment:7th Body/Call of Duty Realisticness/@comment-1260687-20100602012720

Your arms would get tired quickly, and start tremblin and shaking uncontrollably, you wouldn't hit shit due in part to that reason, you'd be ineffective and out of the fight if fire on point targets was required, you wouldn't be able to carry ammunition in volumes sufficient for long-term gunbattles, and the ammunition that you would carry would be bulky and less ergonomic and accessible than magazines for rifles or submachine guns, and you'd be almost completely vulnerable as you stopped to either reload or cycle the action of your weapons (break-action and lever-/pump-action respectively.