SpudFiles

Well...I've restarted the quest for an assault-rifle type launcher.

So far I have a precision 10mm hydraulic tube for a barrel, 10mm BP roundballs as standard ammo..

I used some more seamless tube, 25mm I.D as the main reservoir and the CBHV, wich I have given a tune-up..

The first two testshots I thought something was wrong.
The first one, at just 30 bar shot a hole through my leather welding glove...casually hung over the muzzle.
Usually this catches and stops the projectile..

Hmm.must have been a worn spot?

Second shot I decided to use a capped off section of pipe to catch the projectile.
I haven't been able to relocate the pipe....

Third testfire was done inside of a forktube wich I had braced against the brick wall...
It completely pancaked the lead roundball.....
Looks exactly like those seen in high speed footage of 9mm handgun ammo hitting a steel object...HMM..

All I did was tap the strikerpin with the handle of a small file...
No effort at all.



Definately some potential!!
On all testshots the bolt/slide blew back completely...I was worried blowback would hurt performance...seems it works exactly like it should.


The striker runs through a piston to hit the valvestem.
The valve allows some pressure to exit past the valvestem to drive the coilspring backed piston back and load the next shot.

Clearly not yet finished....
I'll have to tinker with it once a semi/full auto hammer/sear/trigger is added as it will most likely respond a bit differently.
I can add a rubber washer as a one-way valve to give the blowback piston more power if needed and boost up springforce if autoloading isn't smooth enough.

The bolt comes from a powdercatridge nailgun..wich I could not use anyway for legal reasons.So I stripped it for parts to use in a pneumatic.
It's such an exact fit !!
The breech is 100%airtight yet the bolt cycles smoothly...without an O-ring seal! :bounce:

ME LIKIE.

Looks sweet! I was waiting for someone to turn out a quality machine type hammer valve project, looks like it was you! 10mm... that's a good sized BB. I couldn't imagine what it would do to something like a "Zombie". What are your ideas to add to it? A stock of some sorts?

Nick

YES!!!!! I always thought it was a shame the "pnushnikov" was shelved.

So it's not gas piston operated like the original, more direct blowback?

Looks sweet! I was waiting for someone to turn out a quality machine type hammer valve project, looks like it was you! 10mm... that's a good sized BB. I couldn't imagine what it would do to something like a "Zombie". What are your ideas to add to it? A stock ...

That Zombie would probably undie from his living death...

A stock? Good idea..I was wondering about how to hold on to it...a stock might help

@JSR:
It's not direct blowback asin the bolt being the means to recock the system.
It's more like an Autococker, a gaspiston behind the hammervalve.

If this is sufficient I'll go with this, but a gasram around the barrel is in the bag of tricks in case I need to beef up the springforce or if the hammer is too hard to operate..

The 10mm roundballs fit real nice but pressing them in might be just a litte too hard for the current spring.
Rather than sanding the breech to make loading smoother I would lean towards beefing up the spring to get the job done.

A testfire will tell if some extra force is needed to drive the bolt back.

OUCH!!!!

Brian the brain wrote:

Looks sweet! I was waiting for someone to turn out a quality machine type hammer valve project, looks like it was you! 10mm... that's a good sized BB. I couldn't imagine what it would do to something like a "Zombie". What are your ideas to add to it? A stock ...

That Zombie would probably undie from his living death...

A stock? Good idea..I was wondering about how to hold on to it...a stock might help

HAHAHA VERY FUNNY. VERY VERY FUNNY. Will it look like the Pnushnikov or the Caselman or what? That's what I ment...

Looks like the Zombie is no longer, no longer with us
Very good looking pancake!

Nick

I have no idea what it will look like.
I'm making this up as I go.

I don't plan on a particular look..The parts needed to make it work will determine the shape.
I'm expecting to end up with some sick cross between a Caselman, Thompson, MP 40 something like that.

Based on what parts are required and the way it functions...it will look pretty much like a submachinegun, but with a paintballbottle attached.

Some of the stuff on it right now is just temporary.
I just swapped the Allen bolt on the strikerpin for a shorter one for instance.

I gotcha. Should look sick. ever thought about using pellets other than bb's?
Maybe machine a metal. hop-up like the ones used in airsoft guns. Could improve something..

Nick

Brian the brain wrote:OUCH!!!!

Indeed! Bring on the dakka!

Working on the dakka buddy...

I need to make a bullit-mould.
The "standard" muzzleloader balls are running out...and they are just a bit too hard to push into the barrel.
I could do it manually, but for this to work I would need a spring so beefy it would hinder recoil.

Now...I cleaned her up, took away some bulk...and got her to cycle to the point where a second round is about to be chambered...only to grind to a stop about halfway in.

Custom slugs should fix that.
I still have to wrap my head around the issue of the hammer, sear and trigger and how to mount them on the launcher.

The reason I said Pnuschnikov/Caselman:

I wanted to keep my options open. The Caselman is an open-bolt design.
Not something I prefer, but due to it's simplicity I recon I'd have a working machinegun by now if I'd gone that route....

The Pnuschnikov however seemed overcomplicated.Locking the bolt, releasing it via an airram...
I don't know.
I guess the testing I have done so far indicates there was no need for a lock.

I'm just figuring out the simplest way to build a closed-bolt machinegun.
Eventually I'll get it just right.
Pancakes for everyone!!

Brian the brain wrote:I wanted to keep my options open. The Caselman is an open-bolt design.
Not something I prefer, but due to it's simplicity I recon I'd have a working machinegun by now if I'd gone that route....

The Pnuschnikov however seemed overcomplicated.Locking the bolt, releasing it via an airram...
I don't know.
I guess the testing I have done so far indicates there was no need for a lock.

I think I said this when you were making the pnushnikov. If this doesn't need a closed bolt, a pneumatic certainly doesn't.

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You have a point...


So...Open bolt it is,
Made the semi-auto part work today.

I want to make a toggle switch to disable the semi-catch.
( and smoothen the catch...it didn't release on the last shot)

That will enable me to switch between semi and full auto.

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Usually I can figure out how a design works, but this one is something unique to me. Could someone explain how it works, or maybe a rough paint diagram. BTW for the projectile have you tried loose10mm bullets, they are ment for reloading caetriges, and if they r too tight you can keep a piece of barrel material in a vice and hammer then through to size , that seems easier then casting bullets

It might be a one of a kind solution...but I doubt it.

I made it up myself...I needed a trigger and a stopper.

When the trigger is pulled and held down the bolt comes back, that stopper should hold the bolt untill the trigger is released again.
Once the trigger is released, the stopper is no longer blocked by the triggerthingy,,and the bolt slides forward and engages the trigger.

Shown here in firing position:

Imagine what happens when you pull the trigger and the bolt hits the valve, then gets pushed back by the pressure:

Oh..and the yellow stopper is not that square in reality.It's rounded off a bit to work smoothly.
It can swing both ways.It can turn right to allow the bolt to pass, and in case the trigger is not pressed, it can swing left to allow the bolt to pass forward to the trigger-thingy.

You can see that getting the yellow stopper out of the way would turn this full auto....

Brian the brain wrote:Made the semi-auto part work today.

Oh yes...

Maybe you need a heavier bolt though, seems to come back awfully quickly...