Just finding out that I need smaller drill bits. 0.3mm isn't good enough for the Albion Alloys tubing I have so my Defiant, and any other kit that I am replacing the pittot tube with brass rod, will not be as near to scale as they should. The problem all stems from the cutting of the tube. Side cutters are right out as they will crush the brass tube which has walls of roughly 0.1mm thickness. The only other method that I can think of is to roll the tube under a sharp knife to score then cut through the tubing. This works to an extent, however the interior of the tube requires to be cleaned out as cutting the tube deforms it but nowhere as badly as using cutters does so it still requires to be cleaned out and at the moment the smallest sized tube I can do that with has an outside diameter (o.d.) of 0.5mm which equates to a whopping 35mm when scaled up from 1/72 scale.
I do have smaller o.d. tubing but as the smallest drill bit is a whopping 0.3mm any tubing I have that has in internal diameter smaller than that will have to for now be the smallest outer part of a two part or more set of tubes.

Ordering smaller drill bits tomorrow which should go down to 0.1mm. This sounds small but I did get a sample pack from Albion Alloys a few years ago when I was last at Telford which contains a tube with an i.d. of 0.2mm and this is the smallest I have at the moment and I'm not touching it until I get those new drill bits!
The Defiant will just have to make do with a cannon sized tittot tube.
Gondor