Semi Plans-Need Input

[Floyd]

I haven't been on in a while, but with the coming of the summer break and inactivity I have been itching to make another gun.

Well I recently came into possession of two perfect airsoft barrels. Both about 9 inches.



With one I plan to make a high powered single shot stick gun.

With the other I plan to try and make a semiautomatic airsoft gun. Here is a really quick sketch of my plans.



The red part is the main chamber which will most likely be 1 or 2 inch PVC pipe. The air will then leak through a hose and into a smaller chamber which will be filled moderately fast after each shot. It will use a blowforward bolt and some sort of ghetto magazine.

Now here are my questions for you guys.

1. Which barrel should I use for which, I'm thinking bigger one for the stick gun.

2. Do I even need the little chamber (light blue)

3. Where can I get some 6mm OD brass or metal tube?

This is what I thought would be the easiest way if I am overlooking an easier way or just being stupid please point it out.

Thanks!

[Cosmic Muffin]

1. use the biggest one if you want accuracy.
2. yes you will need the chamber. dont make it too big or too small though.
3 hobby shops or.. bunnings?
hope it helps mate

[Gaderelguitarist]

When designing a semi, air source is usually not your problem (Unless you're going for big bore)

You need to tackle the problem of loading with a magazine, otherwize it's not a true semi.

[Floyd]

Yeah, im thinking along the lines of a ghetto magazine (pen tube) to start and then eventually upgrade to a replaceable one.