SpudFiles

hey JSR how do i cast a barrel for my gun? like 6mm inner diameter and 15mm outer dia.

Do you have some 6mm rod? Can't do much without it.

A good source is printer cartridges.

I would definitely try to find another solution (and there are several) before resorting to casting my own barrel. Where are you located again?

how long does it have to be?

England. and i have a chrome tube that's 1/2" do i put a 6mm tube inside and fill with epoxy and then pull the tube out when its rubbery then it hardens into resin

Surely you have a hobby/model shop near by that stocks brass and aluminium tubing?

Goatz, go to B and Q and walk down the gas and plumbing aisle (something like that) there is usually a load of steel and aluminuim tubes with a perfect I.D. for BBs. If you're not sure just bring a BB with you and check if it fits.
You can also get brass tubes that are perfect for .177 pellets.

http://www.ebay.co.uk/itm/7mm-Brass-K-a ... 5467783298

Typically these have 0.5mm wall thickness so the 7mm OD should have 6mm ID

Normal way to do this is to lay up a fiberglass or carbon fiber tube on a mandrel. Resin alone will be too weak.

well b&q has 8mm brass gas fire tubing can i put that inside the big barrel and fill with epoxy as a spacer?[/code]

What's wrong with getting cheap 6mm tubing from eBay? Seriously, casting a barrel out of epoxy should be a last resort, unless you have some peculiar reason for wanting to do it that I'm not aware of.

<a href="http://www.diy.com/diy/jsp/bq/nav.jsp?a ... d_tube">Go to B&Q and get this</a>

Take a 6mm airsoft pellet with you or whatever you wanted to fire and make sure you get one you can blow the pellet through.

.22 airgun pellets can be fired from it but they are a little loose since they are ~5.5mm and the tube is 6.0mm ID.

Don't faff about making a barrel with epoxy, you'll make a mess and it still won't be as good as a length of that aluminium tube.

Found a video showing the manufacture of carbon fiber tubes.
http://www.youtube.com/watch_popup?v=KfQGtYG7zg8&vq
The could be hand done. Fiberglass cloth could be used instead of the thread shown in the video.

The could be hand done. Fiberglass cloth could be used instead of the thread shown in the video.

It would be cool to have a lighter alternative to steel... unfotunatelly the problem here is that you can't tell how high it is rated

Fiberglass is roughly equivalent to mid-grade aluminum when done correctly. Figure around 30kpsi tensile strength, of course any flaws you have in it will drop that somewhat. Still, compared to metal it has favorable failure characteristics.

I have some ladders and pole trimmers for trees that have fiberglass construction. The tree trimmer is quite strong. The fiberglass is to prevent electrical accidents if you have a line through your tree.
The strength of fiberglass ladders is well known.