Project something

[farcticox1]

Got the semi auto together enough to test fire, it seems to work, no magazine tube yet. The chamber and 1/2" valve are from my old 10mm ball bearing launcher so the air supply is probably over kill. The piston is from an old pneumatic cylinder that is cut down. The red block is aluminium.

The principle

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Part way through drilling the block

Bolt on the side is a stopper with rubber tip to stop BBs rolling out

[KannonKing]

that's a beauty! Can't wait to see it in action!

[farcticox1]

After some experiments with piston length and springs I finally got it working reliably. Needed a heavy spring to stop the piston slamming forward too hard, it was breaking the light springs and had started to push the barrel forward magazine tube holds 30 and feeds 1 at a time consistently.

[farcticox1]

Was building the block into one of my old QEV builds which will look much better, after a bit of test firing it stopped loading, took it apart and the piston feel into pieces going to make a solid stainless one now, probably needs some bleed holes so the action is not so violent as well. More experimenting

[farcticox1]

Made new piston from long 6mm bolt with head cut off and piece of 10mm thick nylon, works really good. Semi auto is now built in to my old single shot.

[hectmarr]

Made new piston from long 6mm bolt with head cut off and piece of 10mm thick nylon, works really good. Semi auto is now built in to my old single shot.
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In good time!! I like the general concept and it seems quite feasible that a hobbyist with few tools could build it. Waiting for your video.