SpudFiles

Im no math wiz, so can anyone double check this ratio for me? Barrel is 3 inches wide, 3 ft long. Chamber is 6 inches wide, 15 inches long. That should be about 1:1.5 barrel:chamber ratio, correct? Which is the proper ratio, yes?

I got 1:1.666 B:C

Close enough to 1:1.5 for me. Thanks!

What ever your chamber is make your barrel double your chamber size!!

jsefcik wrote:What ever your chamber is make your barrel double your chamber size!!

But I thought the chamber had to be bigger to propell the spud (or in my case nerf football) all the way out of the barrel. If I could make the chamber smaller, it would greatly help my purposes but I dont see how that would work as well as a large chamber even accounting for expansion of ignition.

If your chamber is too big and barrel is short your not getting full potential out of your gun

For example 3 foot chamber to a 6 foot barrel , you want your gases to fully burn!

If you can't get the barrel and chamber ratio right you want it close as possible

My piston cannon has a 5 foot barrel and chamber
My barrel should be longer but I'm not made of money !! My pistOn cannon puts golfballs 500 yards and beyond

Pm me if you want

For a given chamber volume, the optimal barrel will be 1.4x bigger than the chamber. Any bigger, and you start to loose performance.

With a constant barrel volume, the results are more complex. This shows that anything above 1.2 hurts performance, but HGDT predicts a steady increase

The wiki knows all!! Also, look at other members c b ratio. I would say your close enough. Also try running different figures through GGDT. Welcome and good luck!!