Let me start off by saying that I'm completely UNqualified to be giving advice about metal working. I'm a semi self-taught hacker with limited ability.

However, for the sake of "getting the ball rolling", I figured I'd post a thread here.

I actually posted this photo on another forum a few months ago but it's certainly more appropriate here. This is an aluminum gun barrel for a 1/35 scale self-propelled gun. It's about 8" long and is made from common aluminum from Home Depot (hey, I ain't building the space shuttle).

http://img385.imageshack.us/img385/6888/gb13ss.jpg (http://imageshack.us/)

It's shown on a Taig lathe that I've had for about a year and a half. I made a special drive dog just for this project (although, I can now use if for other projects). I built the dog using a blank steel arbor, some thin steel strap and some 1/2" aluminum bar. One nice feature of the dog is that I built it in such a way that it can be balanced to keep even small vibration from affecting the workpiece.

The barrel has a slight taper so I used a live center in the offset tailstock. This was the first time I used the live center and the first time I offset the tailstock.

The barrel turned out quite nicely. Of course, I could have BOUGHT one for a tenth the cost of making one...but that's not the point is it :).

Cool stuff. Did you have any problems with chatter when cutting?

Yeah, I have to say I did have some chatter problem as the barrel OD started getting rather small.

The problem was greatly alleviated by keeping the cutting tool VERY sharp. I spent a lot of time honing the edge. That turned out to be a very valuable learning experience. I've become very proficient at tool sharpening!

Because of the angle of that photograph, it's not apparent that the barrel has a taper over it's entire 7.5" length and gets down to about 3/16" just before the muzzle flares (the right hand side of the photo). So that's a long. skinny chunk of metal flapping around!

Nice work!! Let us know how it turns out and please post pics of the finished project.
If you need any advice on processing a part or materials let me know.
I am a tool maker with 25+ years in the trade.
Dan

The barrel is finished although the model isn't completed (same old story).

It turned out just fine:

http://img362.imageshack.us/img362/6793/finb0bh.jpg (http://imageshack.us)

I've also built a few metal barrels for some model rayguns I've made. Did one with an aluminum barrel and one with a brass barrel.

Some things to make your work quicker and easier, not too mention turning out better.
Quick change tool post and carbide inserts.
They make all different kinds of inserts for trurning which would do a great job. Ceramic, carbide, etc.. HSS cutters just blow in comparison.