especially 8" sch 80 fittings.

Okay, I guess I'll be a bit nicer. The basic point behind a pneumatic gun is to play around with pvc parts till you have a design that appeals to you. All you need is....... #1 an air chamber. Even small air chambers will support a long barrel. 150 cubic inches (1' of 4" pipe) will support up to a 1...

Wait a gosh darn flippen second. I just noticed something. Is X in your equation the Barrel:chamber ratio or the chamber:barrel ratio? In your explanation it says B:C ratio but the test data says C:B ratio.

wait just a gosh darn flippen second. Sprinkler valves are not chamber sealing. They are barrel sealing. The only thing is that the GGDT assumes everything to be a piston and the performance estimate was made using a chamber sealing piston as kinda a reference dealio or something like that. Just don...

Okay, the only thing is that two 1" valves will not let the same flow out as one 2" valve. It's all because of the area formula for a circle(pi*r^2) If you double the radius, the area grows by four times. In that case it would require four 1" valves to get the same equivalent.

Wow! That's a dang good fitting graph. Is that measurement in feet per second or miles per hour? Oh yeah, one last thing, is that assuming a 4.2% mix of propane?

just use a tissue or toilet paper as wadding.

Okay, thanks joan, you were correct with the assumption of same chamber/barrel volume and same chamber/barrel legnth and diameter. That equation looks like it will be just what I need, just a little clarification quickly. Could you kindly explain some of your variables. I get that it's velocity squa...

Okay, so here's my situation. I'm sterling scholar for math at my high school(yes pimp, that means you can go to http://www.cvhs.iron.k12.ut.us and look at my pictures for sterling scholar and cross country). For those who don't know what sterling scholar is it's just an academic competition thing. ...

'cause it slides around inside the pipe with ease even though it is a near perfect fit. That's how perfect a fit it really is. Since a golf ball is spherical it only touches at one spot, but once you put it in something as thin as a tissue it's fairly tight.

Okay, so one of the most asked about barrel is the golf ball barrel. Here are some frequently asked questions(and some unfrequent ones too). Q: Why golf balls? A: Simple, a golf ball is made for flight. It's already weighted and it's spherical. This is good for us spudders since most of us don't hav...

okay, I'm too lazy to read all of these posts but my view on burst disks is simple. Go and buy some clear plasic plates or doggy boxes. In fact, you could go to arctic circle and order a salad to go and use the lid and/or box it comes in. Or go to arby's and buy their biggest roast beef sandwitch. I...

just get a 4" to 2" bushing. The schedule 40 fittings will go on any other thickness of pipe because they all have the same OD.

One thing I can suggest is to do the stoichiometry to find the exact pressure that should be put into your meter pipe before injecting the propane into the gun. The only other thing that could suggest is a bolt or cam lock breach. Very nice gun. Should be rather powerful.

Yeah, we are a bit nutz here about grammar and whatnot. In fact, just by typing this message someone will proofread me and fix any and all spelling/grammar errors. That or they will make fun of me for whatever dumb reason I'm posting this message. That's half of the fun of the forum.