I was just too tired after I posted this cannon on SpudFiles last night to come and post it on here.So, here we go!
This is a copper piston-valved marble gun I made in response to lowering temperatures. The chamber is 1x36" type M copper tubing, and the barrel is 1/2x48" type M copper tubing. Marbles fit REALLY well in this pipe. The average diameter of the marbles I've measured has so far been .566". The inside diameter of this tubing is .569". There were little dings in the barrel from construction, and I actually had to use a ramrod to get a marble down to the bottom for the first two or three shots. Now, they slide down, (usually), and then take a while to do it.
The power I've experienced when shooting this gun is awe-inspiring. I shot a marble almost clear through a paperback book, (video at the bottom), and blanks sound like a .22 CB round going off, (if anybody here doesn't know, the CB rounds are the shorter, quieter of the .22 rounds).
The valve is a barrel sealing tee valve. I made the piston by sharpening the end of a scrap length of 1" tubing and punching out a few 1/8" neoprene disks to make up the back centering plug and the front sealing face. I originally had some problems with the piston not sealing against the back of the barrel, but now it seals perfectly. The piston seal inside it's carriage aint to shabby either. I can pilot it by only halfway opening the 1/4" ball valve, with respectable power still.
Anyways, enough yip-yap, and more pictures!
- back.jpg (35.47 KiB) Viewed 2393 times
- full.jpg (27.45 KiB) Viewed 2393 times
That's all the pictures I have. I also made a short video of me shooting through the paperback book, which is found here.
I'm also thinking about making some ballistics gel to shoot into. I got to work today, and it is extreme coincidence that the McMaster bill for all this copper came in yesterday, so I'll have to take money out the bank anyway. I'll probably do the actual shooting on Sunday, though.
