scrap the shotgun...
I have a new idea, it's a crossbow, with 2 differences:
has a pump
has a mag (if possible)
The pump will essentially just be two green connectors spaced apart, with a snapped elastic band round each "wing" and the pump will move up the barrel, and willbe hooked onto the trigger which is in my pistol, the pump is then realeased, and if i can get the mag to work, then one bullet will be pushed up into the barrel, the gun will be fired, the bullet will fly out of the gun, and hopefully return to being hooked into the two green connectors, ready to be pumped again... I will try my best, and since i now have a camera, i will show pictures of my progress (if i have any)