Algodoo

This piston is a generic model to use in firearms for stable ejections, bolt movement, and locking. It is free for anyone to use (but a little reference that I created it - if you use it- is appreciated)

Collision groups used: E, F

I adjusted the frequency so it runs smoothly on my computer. My processor is a bit too fast for Algodoo to handle 60 HZ. you can modify the frequency to accommodate your scenes, but anything too low might result in the mechanism being whacky.

you can modify the mechanism as much as you like. the skin is grouped so you can see the internals easily by moving them to the rear.