9mm SMG project + other HPA BBMG experimentation

[jackssmirkingrevenge]

I was considering a thin (1/64") ply frame in an epoxy sarcophagus, but I want to use this at 800 psi+ so flat sides might not be the best of ideas. Still, the square mag would remove the need for a separate chamber. I'll see when I get home, looks like it's going to be a long bloody workday

[psycix]

800 psi+

epoxy sarcophagus

*cough*Welded/machined steel*cough*



But I think that with some steel plates, a handful of good bolts and lots of epoxy you might be able to hold it together. Just add LOTS of bolts left and right to the channels.

[Brian the brain]

Wasn't it some German officer named Schrapnel that thought of that first?

[jackssmirkingrevenge]

Wasn't it some German officer named Schrapnel that thought of that first?

Henry Shrapnel was British!

good one though

*cough*Welded/machined steel*cough*

Too expensive/complicated, I do have contacts that could machine the crap I come up with but they'd do it for a price and I have better things to spend my money on at the moment.

But I think that with some steel plates, a handful of good bolts and lots of epoxy you might be able to hold it together. Just add LOTS of bolts left and right to the channels.

Are you from Hamas by any chance

[jackssmirkingrevenge]

Update: I'm making a 4.5mm prototype to link up with the bottle and valve, based on this design. The BBs are held in barrel diameter tubing, however there is a small hole from where the air feeds (the aluminium tube which feeds into the copper tube not visible in the photo) that leads directly in the chamber before the detent, hopefully this will provide sufficient air for the shot without disrupting feeding. I just need to cover the semi-circular section from the tube mag to the detent and it's ready for a fairly complex casting.

[POLAND_SPUD]

it would be cool if it worked but I doubt it will... I suppose it will stop stoppages but double (and triple) feds are to be expected with it IMO... lol PUI

I wish I had never started any semi/fulllauto projects.. they are soooo depressing
edit
grammar... I hope I improved it

[jackssmirkingrevenge]

it would be cool if it worked but I doubt it will... I suppose it will stop stoppages but double (and triple) feds are to be expected with it IMO...

We'll find out in less than 24 hours

lol PUI

We have to do a spudfiles barhopping gathering some day maybe after the European championships hehe. I've actually taken to shutting down and disconnecting my PC before going out, that way if I'm in no state to switch it on then the internets are spared my inebriated ramblings

edit: here's the unit curing, magazine and barrel are all held in an epoxy filled 3/4" thick walled pipe so it should take 850 psi comfortably, but for now I'll just test it at compressor pressures later in the day.

[psycix]

Be patient. Wait for it to cure.

I wonder if it fails or not...
My guess: it spits out all the balls at once, but I hope I'm wrong.
Make sure that detent is tight.

[al-xg]

No air chamber on this one ?

[jackssmirkingrevenge]

My guess: it spits out all the balls at once, but I hope I'm wrong.

Whilst I hate to admit it, it's beginning to look like you're right

PAAAAAAAAAAAPPPPP!!!!!!!!!

[psycix]

beginning to look like

That means you have tried it?
Any chance on some video evidence to put this idea into the pit of fail?

If you still can, try a bypass, filling the chamber mostly via that, and using the flow around the balls (uhg...the flow around the balls?!) merely as a force to transport them.

[jackssmirkingrevenge]

That means you have tried it?
Any chance on some video evidence to put this idea into the pit of fail?

I gave it a few whirls at 110 psi, no go - feeding is erratic at best, if at all. I'm guessing I was a bit optimistic with the bends between the mag tubes and barrel, it seems the BBs are jamming there. I'll try it at 850 psi tomorrow but I'm guessing it's not going to work.

I'll amuse myself with some velocity record attempts while I think of a better solution, if I get an airsoft BB significantly over mach 1 it will be enough WIN! to compensate

[Brian the brain]

That will be just sick!
What exactly are you trying to achive with the mag set-up?

Are you using something to hold back each BB?
When enough pressure is reached to fire the first one, doesn't that automaticly mean the rest will also follow??

Sure you'll get BRRRRRRRRRRRRRRRRRRRRRRRRRRRRP..


If you want the daka-daka thing ...you're back to QEV-pop-off or rattlesnake..

at compressor pressures that would be rattle-snail..LOL

[jackssmirkingrevenge]

Are you using something to hold back each BB?
When enough pressure is reached to fire the first one, doesn't that automaticly mean the rest will also follow??

Sure you'll get BRRRRRRRRRRRRRRRRRRRRRRRRRRRRP...

I put a detent, the idea is that it catches each BB as they pass and slows down the rate of fire, not quite dakka dakka but fairly reasonable, like what I achieved with this.

[youtube][/youtube]

If you want the daka-daka thing ...you're back to QEV-pop-off or rattlesnake...

The whole idea of dakka-dakka was to maximise individual shot power to compensate for the fact that I was stuck with compressor pressures - but now that I have HPA on tap, I want to milk it for all its worth

[Brian the brain]

but now that I have HPA on tap, I want to milk it for all its worth

I understand....