New Combustion

[Bluerift]

I just built a new combustion. It has a 3 inch chamber that is a foot long and that goes out to a 1.5 inch barrel that is 5 feet long. I was wondering should I deacrease my barrel size? And is this a good setup? Hopefully I can post pictures soon

[CS]

3X12=36
1.5x60=90
36/90=.4:1
So that basically means that ya your barrel is way to big and/ or your chamber is to small. I dont know how to tell you wether or not you have a good setup because quite frankly I cant see any pictures. A little advice, take pictures and then post. Incase you dont know a whole lot about CB ratios, 1:1 is a good ratio for first time spudders. Remeber yours was .4:1 so you need to either double you chamber size or chop your barrel in half so that you can shoot farther.

[boilingleadbath]

...pimpmann22, you have had an offical brain lapse.
Ratios go by volume; thus:
3*3*12 = 108
1.5*1.5*60 = 135
Thus, the ratio .s .8:1

This is the optimum length for your barrel (or darn close). Don't shorten it, and don't make it longer - you'll only lose power.
see the <a href="http://www.burntlatke.com/15cb.html">this</a> for details.

[CS]

What was I thinking? Thank you for correcting me BLB.

[nodnarbisc]

your both wrong. use pi*radius squared*hight to find th volume. the pipes arent 2 dementional pimpman and they arent square pipe either boilingleadbath.

[boilingleadbath]

Yes, but the pi terms cancel out.
...unless you are using a square barrel/chamber. Which I don't recomend, because square is a vary poor shape for a pressure vessel... I forget the wording for the reason, but basical it's because you get a bending force, instead of a pure tension force... and materials can't take as much force like that.