SpudFiles

this is a semi-auto design i thought of, not sure if its original or not but hee it is, dont think i will be able to make it because i dont have a lathe and stuff but i just thought i would show it.
what you think?

thats a hell smart idea although i dont think you would need a lathe, you could just use PVC or copper or something else

yea thanks, its really just the piston thats the hard part without a lathe

It is basically a blow forward valve without the blow through aspect, and should work fine.

The detent would have to be closer to the magazine though as it will not prevent double feeding in the current position.

The only problem is the chance of inconsistency from shot to shot in the pressure washer opening time, and therefore in power.

A high pressure solenoid valve could fix this, or a system with an unbalanced pilot system (but piloting would be triggered by more pressure instead of venting, similar to the piloting hybrid piston designs).
But I guess one could just learn to press the trigger down with consistent speed.

i was thinking if you use steel bbs you could just use a strong magnet to hold the bbs in place plus with a strong enough spring on the piston the opening time of the pressure washer is not a concern for by the time the pistons opened the pressure washer would be open and with high pressure all you need is the pressure behind the piston to fire it

I think a BFB design where the air goes through the bolt would be better because in yours there is a lot of dead volume between the valve and the projectile.

I tend to agree with Vincenzo. The bolt would also be much lighter. Look into Clide's GB semi for a physical prototype (which actually works very well). He also used an awesome main valve.

yes i have seen that one before but i was thinking that something that would seal the mag of would make it easier to use high pressure without having to worry about having to seal it and have less issu with duble feeding, also if you get the spring strong enough you could maybe get it full auto? dose anyone know where to find any links of some blow forward bolts?

Here is Clide's.

if you used jsr sealing popoff style this would work perfect, the "deadspace" others are talking about would be used as chamber volume, when the desired pressure is reached the bb would pass through the seal. zero valve opening time and semi-auto

the unit:
that is pretty much what i was thinking, also you wouldnt have the flow restrictions that would come with having the air go though the bolt which then would be able to seal the mag 100%