thats a good design you got there Starman!!

I think the big difference would be the cost!

as for one being better than the other.... I would say the copper would be better and more accurate than the pvc but I guess it all depends on the builder.

it was probably DWV.......

I like the B-D for the simplicity of its design, but I fear it will damage the shell of the pumkin. I read a thread on a double B-D design... one in front of the other to allow more psi in the chamber. So that got me to thinking.. if I used a ball valve in-line with a B-D. Then the pumkin would star...

the title to my truck so I can stop making those high payments!! 8)

Hmmm.... Where to start... Well I have decided to go big...giant.... OK Gigantic! I'm going to launch pumpkins! Thats right 8-10LB PUMPKINS! I found out that there are a few local meet here in Washinton. A friend of mine is on a team with a trebuchet. They are cool but not my style. I have a few ide...

That inhales vigorously!!

Glad to see your still around Gippeto! You always sound good advice.

Hey where did the "4Sale" page go? Didn't we use to have one!?!?!

I know I bought stuff before......

could use a little more info....

what are you shooting?

so I'm guessing you are looking to build a semi-auto? 8)

what type of valve are you thinking of using?

Just wanted to say I'm BACK!!!

Its been a long time since I've been on.......or made a cannon for that matter!

Bremerton Washington!!

You will want to buy the balls with the thickes shell you can find!
If the shell is to thin they break under less pressure.

I like the design.... I have been considering a mini my self!

Yeah and if the ignitor blows out of the cap it could break her finger! I have seen caps and ignitors blow from cannons...