How far in can your barrel go into your chamber ?

[tatfree]

My barrel will be .75" ID by 1" OD and 36" long. My chamber is going to be 2.75" ID. I will probably make the chamber between 3" to 4" long depending on if I can bring that barrel through it by more than an inch or two.( going for 1.5-1 ration Chamber to barrel).
I know that I must deduct the displacment of the barrel that protrudes into the chamber when designing te volume of the chamber.
Seems to be it would hurt performance the more that barrel comes into the chamber, but that's just me. Can anyone clear this up for me.
How much can the barrel come inside your chamber before it sacrafices perfomance ?
I have the Cam and groove couplers by the way.


Thanks

[jackssmirkingrevenge]

edit: my bad, didn't realise this was the combustion section

[tatfree]

Spray and pray (What you all call it )style .

The barrel goes into the combustion chamber, not just butts up against it .

I'll try and find some pics others have posted.

[psycix]

If the chamber diameter is large enough: all the way to the back. (Keep a bit of space from the back wall of course. I'd go for the barrel ID.)
Its called coaxial.

In combustions, coaxial setups will have a negative effect on the burn rate, as the flame front has to move around the barrel.
It doesn't matter much though, the effects are minimal.
And if the chamber is large enough, the extra barrel length will just add a lot of power.

[Brian the brain]

And if you have a cleanout cap at the back, this means you can breechload it.

Slap a tater on the barrel from the back, without pushing it all the way in gives you a -sort-off- burstdisc effect..

just leave a tiny bit of the spud " uncut"
It will allow for some extra pressure build-up before it gets launched.