Algodoo

Up to fire, left raises the gun up, right does the downwards,
and down to reload, meaning if a bullet gets stuck there
press down and it will reload. If the thing that keeps the bullets
in place (I don't know how it's named) isn't in a good positon
press a or d to make it rotate around.
Don't mess around with the tabs above, because it will mess
up the gun. Updates coming soon!
Now You can put infinite bullets because it's reloadibile and it'll fire for ever until a glich comes up, but now in a different way.
Once the simulation is started, press b to lock the bullets in place. Then press up to fire. When the bullets are stuck,
press down or drag them. When the bullets are gone, press b, then take the thing that holded the bullets together out and away,
open the trap, switch to drag mode, press the disable rotation button, and then get the other holder in the gun (warning: frustating thing to do!).
When the is inside, close the trap and press to lock the bullets in place. After that, you can do it as many times as you want.