This item from Fineline Model Products features includes a 4" length of stainless steel tube 1.65mm Outside Diameter 1.20 mm Inside Diameter.  This would be the ideal thing for a gun barrel.

This is a list of the sizes they carry.

• ST 16  1.65mm OD  1.20mm ID 

• ST 19  1.10mm OD  0.68mm ID 

• ST 23  0.63mm OD  0.33mm ID 

• ST 30  0.30mm OD  0.15mm ID 

Modellers are always looking for fine metal tubing for making gun barrels and this tubing is ideal for that.  You can cut this tubing into smaller lengths by rolling it back and forth under a Stanley knife blade (utility knife blade).  You would get quite a few gun barrels out of this 4 inch piece of tubing.

They also sell wire mesh and many other modelling items.

You can purchase these and other fine model products directly their e-bay store at http://stores.shop.ebay.co.uk/Fineline-Model-Products or from the folloing address.   

Fineline Model Products
PO Box 14
Bridgnorth
Shropshire
WV16 5HY
United Kingdom

Steve

I would like to thank Fineline Model Products for providing me with this review sample.