Portable bb gun ideas

[cammyd32]

I am making a gun for a competition airsoft fight, the guns must be home-made though.
To have the slightest chance of surviving I need a gun that :
Is robust and strong, and can handle being knocked about a bit,
Reasonably simple design
Needs to be semi auto or auto
Needs to be light and portable
And it needs to be quite powerful,
I do have some ideas at the current based on a reciprocating gas ram, but i am not too sure about it.
It is a big ask, but i am really short on ideas. any help is welcome, thanks 8)

[jackssmirkingrevenge]

BBMG

Simple, full auto, powerful enough for airsoft at even lower pressures.

Here's a ghetto example made with minimal resources.

Your issue here though is air capacity. A 2 or 3 litre pop bottle at 100 psi isn't going to last you more than a few bursts.

The solution depends on your budget.

If you have a wad of cash and somewhere to refill, paintball HPA or CO₂ setup fed through a regulator.

For a sub $100 solution you may want to try the Kobalt CO₂ rig as used here but that still involves needing somewhere to refill the gas.

You can also use propane through a regulator which would be even cheaper.

If you don't want a bulky gas supply, you can always opt for a smaller chamber topped up with an on-board pump.

There, you're no longer short on ideas. Now do some more research

[LovableAirGuns]

pvc pipe and a balloon?

[cammyd32]

Good ideas jsr but i was thinking more along the lines of something that was not a cloud or vortex, as these ideas "waste" a lot of compressed air. If there was an idea which made use of EVERY bit of compressed air even a small tank would go a long way.(perhaps some kind of blowback gas ram.)-That way if you had a couple of medium sized tanks strapped to a belt that could be attached quickly to the gun it would be quite a portable non-compressor-or-pump reliant system,that is what I was thinking. 8)

Also I am looking to spend around 70 English £ on it so any ideas for what I could do for around that money?

also;

pvc pipe and a balloon?

- good idea but a bit too simple

[Slyder2k8]

I saw a video the other day where a guy took 3 3"x18" chambers and built and "airpack". A 90 on four corners and a t in the center on top and bottom. A qd inlet for filling and a qd outlet for connecting to his gun. You could use a small backpack for carry or put shoulder straps directly on it. I havent been at the pneumatics for long but JSR or Tech could tell you the volume and maybe run time on this. I would think for a small chambered gun you would get plenty out of it. I know there are several designs on here that implement a small chamber and semi auto fire rate. If i find the video i will try to post it here.

[jackssmirkingrevenge]

If there was an idea which made use of EVERY bit of compressed air even a small tank would go a long way.(perhaps some kind of blowback gas ram.)-That way if you had a couple of medium sized tanks strapped to a belt that could be attached quickly to the gun it would be quite a portable non-compressor-or-pump reliant system,that is what I was thinking.

The gods of efficiency smile upon your good intentions I can't think of any better example to point you to than this one, you should be able to build it on your budget, even in rip-off Britain (use eBay!)

I think a single high pressure tank would serve you better, it would be a pain to fill if you only had a shock pump or similar but there's fridge compressor and home-built stirrup pump options.

The backpack idea would also work well, though it would be a little bulky in-game. I got 3-4 seconds firing time from a 2 litre chamber at 110 psi with a vortex block BBMG, if you add a detent and restrict airflow from the blowgun you'll get a lot more out of it.