On tonights episode of House, Dr. House went on a road trip to go to a spudgun shooting contest. He had a homemade combustion gun of some sort (maybe another brand gun?), his arch enemy of the spudgun challenge was dude with a BL-520 !! The new episode of house isn't online yet but it will be soon a...

Depending on the size of the tank, if you want a quick and easy gas tank use an one gallon paint can. Sometimes they can be bought clean, if not you can find an old one and clean it out.

You could pump hydraulic fluid into a tank full of air, thereby presurizing the air.

Glad you got it working. After you do that once, you should never have to do it again.

I think I had the same problem, but I'm not sure how I fixed it. I think I right clicked on it and clicked "Run as Administrator".

Yes the main piston is disconnected from the rod. The 1/2" piston doesnt have enough power to move the main piston on its own, but when the 3/16" rod and 1/4" rod get moving it has enough force to unseat the piston. Right now I'm using knee pad foam for a bumper.

I made something similar, the gun it self is a 3" chamber with a 1 1/2" sdr 21 golf ball barrel, QDV. Inside the stock is a 1/2" cpvc cylinder and a HDPE piston, a 3/16" steel rod runs through the stock and connects to the firing rid for the QDV piston. A blowgun connected to the chamber siphons a t...

A bike pump can go to 120 psi, but they were not designed to. I have gone through 3 bike pumps, every time the hose pops off the pump and there is now way to re-attach it.

I think its a good idea, but your going to have to find a good, cheap source to provide you with raw materials. Alternatively members could send you an item to be machined, but that would cost more due to the double postage.

I think you should build a QDV or burst disc @ 50 caliber ( its easy to find 1/2" steel rod to make ammo) . The QDV is more complicated and harder to make but the end result it give you very high flow and can be a breech loader. A burst disc is very simple, and effective. Probably the fastest openin...

I would go with 50 cal.

How did you mount the stock on the chamber?

I like the diagram, I wonder if an air cushion could be used instead of a spring? It would be eaiser to adjust the fired rate by adjusting the air spring pressure.

Look under "A" for accuracy

LOL

Interesting idea, reminds me of a semi-auto shotgun. I would change the piston to be parallel to the barrel also with a system of linkages to load the projectile.