SpudFiles

Hi, i may be new to the forum but i have been reading asmany posts as i can befor i registered. i found all the info really helpfull and i hope you can help me out.
i have an idea for a rile that i want to make for shooting targets

i dont really want to use a spinkler valve and i wnt something that hopefully wont release all the pressure in the canister all at once.
the idea behind this is that once you pull the trigger it releases the bolt and that shoots back and then foward again releasing enough air to propell a bb/pellet.

any ideas on why it wont work??
cheers

Well its not a very efficient design.

To work it would need some horribly powerful springs to hold back the air and it would lose power quite fast if you're thinking of getting multiple shots out of it.

The last point is because its pretty hard to economically get the high pressures you need for a multi-shot resevoir.

And its not a good idea to use unregulated co2 or HP air with improvised valves if thats what you were thinking of.

You could use a QEV (quick exhaust valve) instead if you set it up the right way to release fixed volumes of air into the barrel.

Hmm I'm thinking no. I redesigned this for you. Basically its a chamber sealing valve, These will yeald much better performance than most other valves. Ok so the piston is pushed forward to seal the chamber, As the chamber is filled, the small area behind the piston is filled aswell. The pressure behind the piston holds the piston up against the chamber, Sealing it off (you may need o-rings to acomplish this) Then when the optimum pressure is reached, One squezes the blo-gun trigger and braces themselves.

Yer the hammer/bolt idea is good but kinda hard to achieve. I have experimanted with these for a while and have made amny many designs a lot like yours and still cannot make one.
http://www.spudfiles.com/forums/viewtopic.php?t=2570&
http://www.spudfiles.com/forums/viewtopic.php?t=2537&

Yes, I would advocate going for something like Killagorilla's chamber sealing design. It's simpler.
There is nothing wrong with your design - that is exactly how a lot of excellent pre-charge air rifles work, eg Logun, Quackenbush. It's just that you would have to be able to build this within very high tolerances with very good seals to get it right.
Good luck with whatever method you choose and don't forget to show us all how it works/looks.