This is my first Instructables. Sorry about the photos but I think you’ll get the general idea. I was dismantling it when I took the photos. This will shoot grapes out of sight at 5bar/60psi. This can shoot more than grapes if you shove a cotton ball in first, thus making it a blunderbuss. I TAKE ABSOLUTELY NO RESPONSIBILITY FOR WHAT YOU DO WITH THIS!!! It will shoot a 2inch nail through a rat. You can also attach a bigger barrel with some tape and rubber. Happy figuring out.

Step 1: Parts

Pipe with valve (plastic or metal, I used copper pipe)

Tubeless tire valve

Drill with bits

Tape, I used duct tape

Rubber, blown inertube works well

Air Pump

Step 2: Drilling the Bottle and Attaching Valve

Depends what kind of valve you use just drill a whole that’s pretty snug in the bottom of the bottle right in the middle. Then you can just get a dowel that will fit in the widest part of the valve and feed it through the mouth of the bottle you’ll have to push pretty hard unless you have the thingy for pulling the valve through.

Step 3: Attaching Bottle

You’ll have to look at the photos but you can either make it out of tape and rubber or just tape. Do it so it’s a very snug fit you can put some kind of lubricant on it then just wrap around the neck of the bottle tightly and then wrap it all with rubber. Now you’re done if you have any questions feel free to ask