SpudFiles

G'day,

I'm currently making a new co-axial bb repeater at the moment. I needed to come up with something very strong, threaded, smooth and very cheap to use as the outside chamber pipe.

I came up with this. I simply bought a meter of 25mm aluminium tube, and 60cm of 25mm poly pipe. What I found astounding was the tube fitted absolutely perfectly inside the poly. It was a perfectly tight fit. Almost too perfect...

I'm planning on making this a repeater by having a pop off valve with a very strong spring installed in it behind the piston, I've got a machined hardwood piston that's a perfect fit and I plan on putting a spring behind that. I'll also stick a spring behind the trigger lever mechanism, which should hopefully add a bit more force into closing the pop off valve and resealing it all quickly. I plan on going up to 400psi, and with using a 6mm airsoft barrel, I should be able to get quite a few high powered shots.

Tell us what ya think.

where did you get the aluminium from mate ive been looking EVERYWHERE

nice find and cant wait!!

Bunnings mate. When I saw it I just licked my lips and said MINE! it's in the "mouldings" section. For house building and what not. You'll see a rack of 8, 15, 20 and 25mm alu tube. In 1m lengths and 6m lengths. The 1m of 25mm was about... 6 bucks. The poly pipe was 3....You can't go wrong!

the issue still remains of thread strength, though if the pipe was rated to 400psi in the first place, it should work great to strengthen it.
Good luck on your repeater.

threads can be stronger - locking screws.

another thing you can do is to put the pipe in while in the shop put on two end caps and buy it. free alu pipe. (don't blame me)

It's too tight of a fit. I had to get the pipe in with a rubber mallet