SpudFiles

This is my latest project, the body is based (loosely) off of the KRISS smg.

SPECS:

Firing pressure: 75 psi via pop off valve.
Firing valve: 1/4'' QEV.
Chamber: Co2 tank, used as air tank.

This gun use a QEV modded for full auto, with a 75psi pop off valve, to pulse air from an old co2 tank, into a small could chamber.

Each pulse fires aprox 12-20 bbs, the chamber will hold about 150.

Video:
[youtube][/youtube]

The shell of the gun was made from 2 sheets of 1/2'' thick abs plastic that i got from work. The shell is not yet compete, but i thought i would see if anyone had any ideas for improvement on the overall design.

Do you get any jamming problems with a full load of BB's? Looks like it's got a fair amount of pep to it.

sounds great , but if it fires 12 bbs every time, how is the accuracy?

Looks cool, how did you cut the plastic?

jrrdw wrote:Do you get any jamming problems with a full load of BB's?.

Sometimes, but not very often. and when it does jam, a little shake fixes it.

wyz2285 wrote:sounds great , but if it fires 12 bbs every time, how is the accuracy?

Its about as good as any other BBMG with a 4'' barrel.
i can hit a pop can from 25 feet

clemsonguy1125 wrote:Looks cool, how did you cut the plastic?

With a jig saw, a drill, and a dremel.

Interesting. Quite a short barrel you got there, pressure needs to be upped

Shame about the multiple BBS per pulse though.

Have you seen the Umarex Steel Storm magazine?



It combines a BB chamber with a spring loaded magazine, so you get high capacity which requires no mag changes or extra BB pouring.

We had discussed this concept a long time ago on Spudtech (large BB chamber feeding a smaller firing chamber to reduce losses due to dead space.) but nothing came out of it.

Jack, I would love some more info on how that magazine works.
Possibly a diagram?

jhalek90 wrote:Possibly a diagram?

This is basically how I understand it:

okay, i assume the air enters the bottom tube at someplace behind the bb's...
would that be correct?

jhalek90 wrote:okay, i assume the air enters the bottom tube at someplace behind the bb's...
would that be correct?

That is just the magazine feed, I assume it has some sort of ratcheted hammer mechanism to release the air. Still waiting for someone *cough* to find the time to dismantle his

Ahh, I see now. I was confused.

So it's like a hopper, feeding into a magazine.
Seems like a decent idea to me.

I might build a pistol with that concept...

Edit: as for a use in this design, you were talking about a large"hopper" feeding into the bb chamber, possibly via a ballvale or something similar...If I understand correctly.

Sounds like a good idea, I could replace one of the pipe nipples on the chamber with a "t" fitting that goes to a hopper/ball valve.

You could potentially use a large three way ball valve, and the inside of the ball valve could be the "firing chamber".


_______[BB hopper]
____________::
[barrel]---[ball valve]---[air source]