SpudFiles

this is the wrong topic for this but is there a chamber to barrel ratio thats good for penguns

Big as you can, tiny calibre means you need to maximise other parameters for decent performance.

so the longer the barrel the better? I thought friction would slow the projectile down?

There is an optimal length for all barrels. If you have a really short barrel it will be inefficient, if it's too long it will have too much friction and will decrease performance.
In pen gun calibres to make the barrel long enough to have too much friction it would have to be a few feet long though.

Feel free anyone to correct me if I'm wrong haha