Algodoo

I realised another prinicple was in action in my small scale delayed-blowback gun, and that was, basically, a Tappet effect by the bullet casing, on the bolt.
So I proceeded to make a gun that operates on that principle; one that was adopted by Winchester in the inter-war period.
(But that was about short gas piston movement; a thing Phun guns typically never have).

Same operation as the other 2 recent guns;
Press R, then F, F, R.
- You will have to pull the bolt all the way back first.
(This one doesn't work full-auto, though; it'll fire two shots, then require you to:
(Press F. R. pull the bolt back all the way, with enough force to jerk the gun back a little [so that the little blue disc goes up], then press F, R, R, F, R)
(Pull the bolt back again to manually rechamber)

Decided to gussy this one up, so it has an ejector port that opens up, which spent cases pop out of.
You'll know the gun is in battery when the lever above the chamber is up.


Incidentally, this simplified mechanism allows for even stronger bullets, based on scale, but it does also use simple bullets; these don't have the time device attatched, so the recoil operation is as soon as the bullet is fired.