Assuming thin washers, it should be fine. I'd go with 1.5" though, that will give you 225% area (and therefore available force) over the 1". The washers are probably 1 mm, if not less, thick. Alright, sounds like a plan. Now to do up a parts list, and figure out the labyrinth of which is McMaster-C...

I was thinking a rubber washer between two steel washers, maybe.. 1 inch diameter?

Or maybe a custom epoxy O-Ring head. Would that be more lightweight?

Oops, aha. 60 p.s.i Edit>> That's running off 100p.s.i, but I could easily amp it up to a max of 700 p.s.i; Actually, technically not true. I could only bring it to the pipings bursting pressure. Barrel too short means that at the point of projectile leaving the barrel, there is still a lot of air l...

452 FPS.

But it says something 'bout how my barrel restricts flow, and with anything under 12 inches, the barrel is too short according to GGDT.

Well, according to GGDT, I have plenty of air blowing the projectile out my barrel, and I can only see turbulence and other unforseen harm coming from the excess air that would otherwise screw with my accuracy, and the blow-back valve is pretty direct, in relation to dead space, and I can see it wor...

Okay, so update. I intend to use a palmers brass barrel unless somebody can tell me another material to use as a barrel, so basically this is a calling out to all who have created pneumatic paintball guns in the past. And considering I don't have the slightest clue how to work McMaster, due to it's ...

So would restriction or dead space be better? I'm confused here as well. But I'm guessing it has something to do with not enough air. Or something.. Either way, I'm going to use 1 inch fittings, which leaves me with 3inches cubed of dead space, but it's also giving me more flow, thusly increasing th...

So I should use a .5inch elbow? Would that not restrict air flow? On the program, even with all the dead space I'm still hitting very high speeds and respectable distances. So I don't know if this is very necessary. EDIT> Tested with the .5 inch elbow, and it cranked up the Velocity but Range decrea...

Well, I have it set as 3in cubed. Because it's just a one inch ninety degree elbow. That should be about right, correct?

Ah. Thank you. Back to the program.

I will keep you updated.

Hmm, well. I can give you the numbers I have in for the unknown variables listed in above post if that would help. Flow Coef : 35% Seat Diam : 2 in (I took this to be what the ID of the pipe will be, as in, the diameter of my rubber washers. Open Time : 2.5 milliseconds Dwell Time : 0 milliseconds

.68 diameter, 3.201g mass. Using a .685 diameter barrel.

So far it's going slow due to me being out so much during spring break. But I am stumped on one last number, I am getting absurd ammounts of FPS and range, and I think it is due to either Flow Coefficiency, Seat Diameter, Open Time, or Dwell Time. So can anyone help me? I mean, I'm getting 412 FPS o...

Wow, thanks alot! Time to work out the ideal numbers and get this thing into production.

Well, there's the two pressure chambers, the left on is the one which has the air to shoot the projectile. The one on the right is sealed in to prevent air waste and will only consist of around 0.1 cubic inches, at most. It's basically pipe being flush with a size up piece of pipe, with rubber washe...