I am so frustrated, why can't I use it? I press the left on the dpad and whenever I try to pick more ammo it saids cannot carry anymore... Why cant I pick up any more ammo or use the gun? Whenever I pull it out it and I pull the right trigger nothing comes out? Am I full of the ammo or what has happen for me not use this weapon. I used it many times before without any issues. Please help any help will be greatly appreciated!