Anyways. Here are the barrel dimensions.
Battleship turret. The single-barrel version is exactly the same as the twin, so just did it once. The diameter of the barrel can still increase slightly as it isn't touching the edges (but sketchup glitches up if I make it touch)... The length is measured from the closest point to the end where it can still be braced against the turret. I'd like to avoid joining the barrels together if I can.
![Image](http://i41.tinypic.com/66dklu.jpg)
http://i41.tinypic.com/66dklu.jpg
Cruiser-grade turrets:
![Image](http://i42.tinypic.com/xbldnp.jpg)
http://i42.tinypic.com/xbldnp.jpg
![Image](http://i41.tinypic.com/15gf12g.jpg)
http://i41.tinypic.com/15gf12g.jpg
![Image](http://i41.tinypic.com/2h7e42e.jpg)
http://i41.tinypic.com/2h7e42e.jpg
As you can see, the quads are the most troublesome, with the longest and thinnest barrels. They'll be getting edits at any rate, and most likely will require the barrels to be joined. I might scrap them and start again, depending on how I fare with the edits.
Do you think the battleship and other cruiser turrets will be fine as they are?
Also my main reason for wishing to have the barrels separately, it allows a little customisation, such as posing turrets in elevated positions, or the option to create either a single gun or a twin gun as the turret body is the same.