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Blow back based design

Posted: Tue Aug 26, 2008 2:22 pm
by trollhameran
Would it work if you had the barrel and chamber sealed by o rings rather than by welding or using compression fittings, so that when chamber moves forward, a bar will hit a hammer valve, which will fill the gun with air, then the chamber will move back, due to the pressure pushing it, exposing holes in the barrel, firing the projectile, then when the chamber is empty, a spring will move the chamber back into the beginning position, ready to start again.

It sounds complicated...and I assure you it is :lol: not really, i will try to draw up a diagram explaining it.

Edit: Ive made a diagram... Its a bit jumbled so I hope it makes sense :?

Image

Posted: Wed Aug 27, 2008 2:48 am
by MaxuS the 2nd
Your explanation sounds just like how a Spyder Paintball Gun works.

Posted: Thu Aug 28, 2008 11:28 am
by trollhameran
Got a diagram of one of them you can post?

Posted: Thu Aug 28, 2008 12:14 pm
by MaxuS the 2nd
Sure.

Image

Posted: Thu Aug 28, 2008 12:40 pm
by trollhameran
Thanks man, it would be similar to that, except rather than having a moving bolt, the whole chamber moves back and forward over the barrel.

Posted: Thu Aug 28, 2008 1:11 pm
by MaxuS the 2nd
Yeah I realised the difference after reading your explanation through again.

Posted: Thu Aug 28, 2008 1:23 pm
by trollhameran
Do you think it would work?

Posted: Thu Aug 28, 2008 2:01 pm
by MaxuS the 2nd
Yeah it looks like it should. Although it could be tricky getting seals on all the parts. I was actually going to install something similar into one of my guns in the near future.

Posted: Thu Aug 28, 2008 2:33 pm
by trollhameran
Cool. The way I have set it out should work with just 3 o rings between the chamber and the barrel, and the chamber would hopefully move no more than 10mm. Hopefully i will get a chance to test it soon, because if it works, it could be used for full auto, or changed to semi auto by just removing the spring, and re cocking by hand.

Posted: Thu Aug 28, 2008 2:45 pm
by Sticky_Tape
It wouldn't be semi by recocking by hand that would ba a repeater.

Posted: Thu Aug 28, 2008 2:48 pm
by trollhameran
Woops my mistake, well it would be easy to switch between semi and full, it would fire full auto if you held the trigger down, but if you pulled the trigger then let go, the trigger the re-catch on the chamber as it comes back.

Posted: Thu Aug 28, 2008 2:52 pm
by Sticky_Tape
Here you go.

Posted: Thu Aug 28, 2008 2:56 pm
by trollhameran
Oooooh a cookie :D

Posted: Fri Aug 29, 2008 1:01 pm
by trollhameran
I figured if I can fit a barrel into the plunger on a syringe then it will make a perfect starting point for this design.