Semi-Auto Pneumatic Design

[jackssmirkingrevenge]

something similar was used on BTB's lever action gun

Actually the idea is much older than that the problem with tube magazines in line with the barrel is the limited capacity and the obligation to have them spring loaded.

If your seal is good enough though, you don't even need a firing valve.

[POLAND_SPUD]

yeah I know that the idea is much older...

I wasn't aiming at creating a tube magazine but at a vertical bolt which won't restrict flow...
as you can see this can be easily improved to allow feeding from a hopper and I suppose it could be build using standard fittings


BTW thanx for the link I wanted to see it again

[Brian the brain]

Now that's an interesting idea....

I believe I have referred to the girandoni rifle more than enough..It was in my sig at one time.

The airram that operates the bolt is very awkwardly placed...

That could do with some..improving

[sniper hero]

that's a good idea!
with minor improvements this can be a very good hopper system.

the kind of Y shaped piece could be replaced by a T joint and use a spring instead of gravity to feed it(T is easier to get then a Y:D)

[POLAND_SPUD]

uhmm sorry the bolt should be longer than it is - so that it should fully cover the 'hopper' port when it is in 'raised' position (but I suppose that you've already figured that out)

The airram that operates the bolt is very awkwardly placed...

It's just a quick sketchup so it's placed there for simplicity sake... if or when I build it the bolt will be moved up and down using a spring and brake wire attached to an air ram or even pulled manually when used on a repeater

a very good hopper system

well I've been using a hopper for some time with my semi and their biggest drawback is the fact that they obscure sights making aiming difficult and that they shift the centre of mass up... this design is aiming at solving both of these problems

BTW
don't you think that is a good idea to make diagrams using google sketchup ? sure... it takes some time to get used to it but you can even download ready made models of various fittings and make animations etc.
don't you think it's a good idea to encourage people to use it ?

[sniper hero]

google sketch up is very nice to design
I already made some bbmg designs on it

anyone who likes to make a quick protype?