semi idea

[drex]

its kinda like the blow forward only backwards. when the presser leaves the chamber the spring is able to push the bolt forward.

[jackssmirkingrevenge]

its kinda like the blow forward only backwards.

Sort of like blowback, then?

Neat, but it involves a tad more complex sealing that would make it less practical in my opinion.

[drex]

i think if you get it perfect it may be better on performance because it dos not need the air to push the bolt forward against the spring when firing, instead the air pushes back the spring when when filling and the spring moves it forward.

[MaxuS the 2nd]

I never understand any of these ideas unless there's an animation.

[drex]

i'll make one later for ya then.

[trollhameran]

Looks like a workable design, I think I understand it properly, but if not its given me a good idea.

[MaxuS the 2nd]

i'll make one later for ya then.

Well then, thank you very much

[trollhameran]

If the bolt had a rubber seal on the back, which would block off the air supply , then it could possibly work full auto. If made like that, it would be similar to the auto model btb posted a few days ago.