Barrel to chamber size?

[KS-collector]

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?

[ramses]

I got 1:1.666 B:C

[KS-collector]

Close enough to 1:1.5 for me. Thanks!

[jsefcik]

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

[KS-collector]

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.

[jsefcik]

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

[ramses]

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

[mattyzip77]

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!!