I just made a full auto machine gun out of a nerf rapid fire 20. This means that if I ever feel like doing a write-up on it. (which I never will) All of you people in australia can have one!
Anyways. I had some RF20 parts lying around. I picked up the bladder to it. The RF20 bladder is not an airtank. It is actually a peice of thick rubber tube that gets filled with air. The force made by the rubber tube allows the air pressure to remain constant. So instead of having one big burst of air, you have about 3 seconds (well, mine does anyways) of constant air flow. The force isn't much, but it is enough to empty my 17 shot clip and shoot about 75 ft. You can make this out of pentubes for the mag and barrel. (mine is made out of another type of tube though) A RF20. And a valve from an at2k (air tech 2000, also another nerf gun). This thing is pretty easy to make and operate. Here are some pics.
[img][img]http://i44.photobucket.com/albums/f12/p ... e7e608.jpg[/img][/img]
[img][img]http://i44.photobucket.com/albums/f12/p ... 7b92e6.jpg[/img][/img]
The red part has the bladder in it. The pump also came from a RF20.
You start by filling up the magazine. It should be pretty self explanitory on how to do that. Then you pump the gun 20 times. After that you are ready to shoot. That thing before the barrel on top of the red thing is the At2K valve. Now, aim at whatever then you pull the rod behind the valve. Keep it pulled the whole time you want to shoot. I have about one and a half seconds of air flow after thee clip of bullets is gone. So you can esily shoot about twice as much ammo. You can also cut up a bike inner-tube and put it around the bladder. This is called "banding the blader" in the nerf world. It gives the bladder more force to be allowed on the air.
You also need to plug the over release valve on the pump head. Just put some epoxy or hot glue over the hole on the end of the pump head.
