My micro armor collection includes dozens of tanks that were bought in the mid-1970s, and are still in my active forces today.
I have had some barrel loss, but nothing too severe. I have never used any of the techniques described here (superglue, epoxy, varnish, etc.) to re-enforce the barrels.
I don't base my tanks unless I need a base to attach a trailer (like for Churchill crocodiles, or UE Chenillettes with trailers, etc.). And I don't glue down turrets unless they are very small (for example R35 light tanks or AB-41 armored cars).
I do suggest you find a nice set of flat-head tweezers. This, or smooth grip needle-nose pliers (no tread on the grip) are the best way to straighten the occasional bent barrel. You put the barrel between the two flat surfaces of the head and press gently. Rotate 90 degrees and repeat. You are supporting and flattening, rather than re-bending. It stresses the metal less.
I have had the occasional broken barrel (usually from transportation rather than handling), and I have also bought 2nd hand batches with broken barrels. I have found the best replacement barrels are found by clipping the nylon tag-holders the come on most retail clothing these days. You know that annoying bit of nylon, with a rectangle at one end to hold the price tag on, and a cross-bar at the other that anchors it through the threads of the cloth. Clip and keep these as you buy clothes, and you'll soon have a collection of nylon barrels in various lengths and thicknesses. I have thicknesses ranging from HMGs and antennas to 122mm guns (but no 152/155mm guns -- have to use something else at that thickness). Many times there is a step-down taper, allowing you to replicate compound multi-part barrels. A drop of super-glue gel at the end can form a muzzle break when needed.
You'll never have bent-barrel problems with nylon replacement barrels. Go ahead and bend it … it springs right back to it's original shape. Just be careful not to use a noticeably curved piece to begin with … you'll never get that curve out.
Hope that helps.
-Mark
(aka: Mk 1)
