B.A.R. Pnuschnikov full auto prototype

[Brian the brain]

As I was very impressed with the forced blowback design wich was entered in the last competition I felt I had to go for it.

So far I have made the barrel ram wich is supposed to cock the system.
For the moment I made a simple pilot system wich I can fire semi style if I tap the trigger under constant flow.

I plan to get a new QEV for it, modify it and pilot it directy with a pop-off, as I have done before.
The incoming air will be handled by a blowgun, but this time from the reservoir side.
Wich basically means I can place it anywhere and I intend to go for ultimate bullpup.

I'd like to call it the BAR as in Bullpup Assault Rifle, with a wink towards the metric scale for pressure.
But as I have not yet performed the feat of rifling succesfully..I guess
Bullpup Air Ram will have to do..

Pictures speak louder than words so I took some pics of the early stages.
I built the airram with stuff I had lying around and miraculously everything fitted together to form a 95% airtight ram.
It's co-axed around the barrel.
I press fitted QD sleeves into some 28 and 26 mm pipes and some O-rings into the QD sleeves, wich I superglued in place.


I need to fix the moving part of the ram to the ( not yet built) bolt in the back.
I have the perfect rail to make the mag out of BTW.
QEV-pop will give me a much better configuration so I can have the ammo come in from the bottom.

I have the brackets to mount elevated sights too.A must in bullpup design.
The muzzle spacer serves as a mount for the front sight.

I tested the ram by plugging the barrel and it extended really really fast!
All I need to do is regulate the flow coming from the blowgun ( with QEV-pop in place) to make sure the forced blowback system can keep up with the valves.

[Big-E]

I like it a lot! Where did you get that spiffy blowgun?

[Brian the brain]

I scavenge yardsales and flea-markets for stuff like that.
That's where I find most of my unique stuff, like the elevated sight brackets with I.D. of 16 mm.
Just perfect stuff you can't make yourself ad sometimes couldn't even dream up.

Same with my " Old Shatterhand" cannon.
The decorative stuff was all from flea-markets or from work.

I can recommend it to all.

I knew there where blowguns out there with a plug right behind the valvestem.I tapped it to 1/8" and filled up the bottom channel and plugged it.
I had been looking for it for a year now.
Unfortunately it's so old it's seen it's best day.

No matter..I intend to go for QEV-pop-off anyway.

[jackssmirkingrevenge]

Looking very promising, I knew it was a matter of time before you gave something like this a go and still practically sawn-off I see, god forbid you ever fitted a long barrel hehe

I like the blowgun too by the way, very art-decor

[POLAND_SPUD]

I built the airram with stuff

so what is it ? an air cylinder attached coaxially around the barrel and fed with air from it ?

so it's like a pneumatic version of the AK47, right ?

[jackssmirkingrevenge]

so it's like a pneumatic version of the AK47

Let me guess, he'll call it the PNUSHNIKOV^TM

[POLAND_SPUD]

PNUSHNIKOVTM

lol that's a catchy name


lol BTB move the damn airram further from the muzzle... we all know that you have sawn off disorder and one day you'll wake up and saw off the barrel

[Brian the brain]

I stead I'll move the handle forward to the max.
I'm not stupid..

Shat has 1 meter of barrel wich I haven't sawed off all this time and probably never will.
I started out with 90 cm but swapped it for a longer one..for a hammered repeater it felt logical as I need to get the most out of a single reservoir.
Hacking off the barrel would mean hacking off the reservoir as well.

I'm all for compact design, not neccesarily sawed-off.
I have made exagerated bullpup designs before.

Yes, it's a coaxial cilinder wich gets pressurised through a barrelvent located inside.
I might put a piece of flexible hose over the hole to make it work as a check, so the ram will fully profit from the incoming air, while able to drain because of the small blowby between the two tubes.
I always have the option of drilling additional holes at the end of the stroke.
At least I can tune the ram to my needs that way.

Pnuschnikov is a fun name, but it would better apply to the original contest entry by AL-xg( if I remember correctly.)
The gasram in an AK is not coaxial.
I just felt it would all become easier this way.

Right now it functions as a muffler, since nothing is attached.
Finishing this might take a while , if ever, as I plan to get a lathe pretty soon and that would turn this into nothing more than a prototype.

Oh well JSR..

catchy name

.I feel obligated to return the favour now....eventhough I already planned elevated sights.

[jackssmirkingrevenge]

eventhough I already planned elevated sights.

Well, the Newmatics PM-16 is already taken

The gasram in an AK is not coaxial.

To be honest I cannot think of a single self-loader that uses a co-axial piston. Well, no self loading firearms at least, as I've pointed out many times the FX Monsoon uses one:

[Brian the brain]

[youtube][/youtube]


I switched the chamber sealing sawed-off III valve back into barrel sealing, basically cause I'm injured and didn't want to go get a QEV

and I got quite a surprise.
We all know piston valves have better porting but the power is way way beyond anything I've seen a QEV do.Or a piston valve with similar porting size for that matter.
It's made for high flow and has a lightweight nylon piston.
The snapvalve pilots it like crazy!

I only used 200 psi but it feels more powerfull than a 1/2" qev at 400..
( just a feeling until proven ofcourse)
Anyway I'm satisfied.
Much more powerfull than my previous full auto cannons.

Vid is to show the ram working and to show you the new compact design.

[jackssmirkingrevenge]

very impressive! it certainly looks like it would have enough clout to recock a bolt mechanism

Is that with the muzzle blocked off?

Damn, you've got me thinking... full auto 3/4"...

[Brian the brain]

It might need the check inside of the ram to fully recock it.As the ammo exits the barrel pressure will drop immediately inside the ram too.

I'm not sure 2 inches at most of ammo travel left as it passes the vent will give it the time to extend fully.

Anyway..I love the fact I managed to do it this compact...ly..

[POLAND_SPUD]

hmmm interesting...
now the only question now is... why did you mount the airram right at the muzzle?


I just don't like the idea that there are some exposed moving parts on the gun.. that's like asking for accidents to happen

probably you could achieve a similar effect with a simple T... it would be even better if you had a T similar to teh one that psycix machined for me

I wanted to test it once but I couldn't find right springs to fit in it

[Demon]

I am not sure to understand how it works ...

Is there some sort of air cylinder around the barrel? When does it retracts (at trigger pull or not pulled?)

It looks very promising ...

[Brian the brain]

just don't like the idea that there are some exposed moving parts on the gun.. that's like asking for accidents to happen

Almost all automatic firearms have exterior moving parts.A bolt, a slide or breech of somekind.
But thanks for the heads up. I was gonna stay clear of it anyway.

I had originally intended to put a cover over the entire ram, but since I will be gripping it where the wood is, I won't have to worry.
either that or single-handed!!
Who needs to aim if you're " spamming" ballbearings at 'em..

probably you could achieve a similar effect with a simple T...

Al-xg did that in the original version.I wanted to improve it....

Is there some sort of air cylinder around the barrel? When does it retracts (at trigger pull or not pulled?)

Can't see the vid huh?
Yes..there is a cilinder around the barrel, with a piston/tube inside of it.All airtight with O-rings except for the two tubes wich have a very tight fit.

It is filled rapidly with air when, after a shot, the ammo passes a venthole.
So technically, it doesn't do anything at the time of the triggerpull.

It only slams back when the ammo is very near the muzzle, so already going fast.
Very little performance loss to recock the system as opposed to say, a blow forward bolt.

now the only question now is... why did you mount the airram right at the muzzle

?
Again: It's taking advantage of that last bit of air wich would normally be mostly wasted.

The projectile is shot as efficient as with a single shot cannon.No energy is put into reloading mechanics untill the projectile is already up to speed.

All this was pioneered by Al-xg so I won't take any credit for it.
Maybe now you see the genius behind it and why I felt bad he was not among the winners in the competition.

Main reason was his looked bad..

Anyway.I hooked it up to a blowgun and ditched the reg...
I worn out the rubber on the snapvalve really fast. ( sound familiar Jack?)
I had to replace it with better, thicker stuff.
I also inserted a second spring ( coaxed that too) and thereby cranked up the pressure a bit.

I just got MOAR DAKKA baby!!

True dakka-dakk-dakka as was intended.
I was worried about the pressure buildup inside the chamber when the trigger is released...when the gas warms up it might fire the gun by itself, but fortunatly, the snapvalve will only work when pressure rises rapidly..it slowly vents off any buildup.

I'll do a DAKKA vid tomorrow..it looks amazing!!
And somehow..I don't know why ...it sounds like...
A machinegun! 8)