Cartridge ejection system?

[PVC Arsenal 17]

however I highly disagree with separating them completley

Never said they had to be... though I can think of some instances in which they would need to be.

[jackssmirkingrevenge]

there have been several attempts including mine but I know a very down to earth design that can be easily adapted to meet your current design

I always thought that design deserved to do better in the contest than it actually did, shame.

Pretty nice concept but reading the posts I see you had some power issues.
I might use that on my future projects when I'm 100% sure I know how it works and when I'll be able to improve on it. I'm pretty new to piston vales let alone semi auto. Just wanna keep things simple and because it is a sniper I'd like to have that manual action.

The power issue was what stopped me taking it further, I did have a few ideas for refinement but it remained on paper.

In terms of simplicity though, I think a simple blowback mechanism where the air does all the work is probably the simples to make, though I agree that a manual system is better for power.

As to cartridge feed, here's an idea for a gas-driven semi-auto but it could easily be adapted to manual operation:

[FighterAce]

sorry I don't think I explained it well, the diagram should explain everything,

we really ought to find the creator cause the design is fantastic I recall seeing it after I made my deus ex machina in 2007, and to be honest I felt slightly humbled because the design was just so practical and seemed to be the better design of choice in almost all applications I'm suprised I don't see many adaptations of it

this design has been modified to use a sliding barrel bolt, the original I think used a separate sliding bolt but I might be wrong

one of the issues with the original I recall was that the top retaining piece was really narrow and flimsy looking because the friction of the retaining piece had to be minimized so the cartridges didn't slide back with the bolt, a simple piece of springy metal, a leaf spring if you will, put in as shown and a tapper on that part of the barrel/bolt, as shown, should fix this, it will probably be easier to install on the side but I drew it on the top for viewing purposes

Yep this is what I was looking for. Caveman simple and reliable Thanks!

there have been several attempts including mine but I know a very down to earth design that can be easily adapted to meet your current design

I always thought that design deserved to do better in the contest than it actually did, shame.

Pretty nice concept but reading the posts I see you had some power issues.
I might use that on my future projects when I'm 100% sure I know how it works and when I'll be able to improve on it. I'm pretty new to piston vales let alone semi auto. Just wanna keep things simple and because it is a sniper I'd like to have that manual action.

The power issue was what stopped me taking it further, I did have a few ideas for refinement but it remained on paper.

In terms of simplicity though, I think a simple blowback mechanism where the air does all the work is probably the simples to make, though I agree that a manual system is better for power.

As to cartridge feed, here's an idea for a gas-driven semi-auto but it could easily be adapted to manual operation:

That piston design looks very nice, I think it will work very well but I'm afraid I dont have enough space in this gun to put it in.
However... it loooks like it could fit quite nicely into the P90 I've been planning to make after that sniper

Thanks for the replies!

[sinper2006]

there have been several attempts including mine but I know a very down to earth design that can be easily adapted to meet your current design

I recall a cartridge system one of our members (I'd like to credit the person so anyone help me find it if you know it) built where the cartridges were first pushed forward against the barrel and out of the hold of the magazine, a bar attached to the top of the bolt held the cartridge in place in the forward position, but when pulled back the bar stopped blocking the cartridge from exiting so it was pushed out by the fresh cartridge below it. I think the design used a sliding bolt to push the cartridges against the barrel but just as easily it could use a sliding barrel
give me some time to look/draw it up

was it this video by an chance?
[youtube][/youtube] i dont no if im a little late with this o well.
also note i wasn't the creator of this its just in my favorites on youtube 8)

[iknowmy3tables]

no I don't belive thats it I'm not sure how that one really works, but the one I recall was made out of pvc. and one random detail I remember was that may or may not be true was that the magazine spring was made from a sprinkler or sprinkler valve spring? well it should be some where on these forums, any seniors you might recall it help me out if you can