I am going to try and build a new type of paintball/airsoft gun. I guess that a really cheap paintball gun would be a good place to start. It needs to be electronic so I can have different firing modes. the plan is to make a gun that uses magazine instead of a hopper and co2 tank. the magazine will hold the ammo and enough compressed air to shoot off all the shots in the magazine. So I would probably have to mod the paintball gun for this. but anyway I need one really cheap.
