Full automatic blowback

[inonickname]

(Larger spring is far stronger than small spring). Air chamber/ supply is smaller chamber. Large spring (supporting piston) pushes down smaller valve. This allows air to rush in, pushing the piston back (and closing the smaller valve). It pushes the piston back until it exhausts into the barrel. With no load, the piston rushes back and pushes in the small valve, allowing air to rush in and the process to be repeated.

Any thoughts/ideas/comments? I might try to construct something of this manner but I'm limited on tools/materials atm.

[ALIHISGREAT]

from what I understand, it looks like a full-auto hammer valve? with the big red piston knocking it open?

the fault i see is that it would be incredibly hard to tune these springs to give the correct strengths.... and even then i think it would be weak unless a high pressure or high volume of air is used.

[sniper hero]

possible but very hard to make.
maybe if you make a low pressure popoff valve so the piston is hold in place longer and will go more explosive open or something similar to this

[jackssmirkingrevenge]

Some similar variations on the concept here and here, worth reading through.