blow-forward bolt

[Scope]

Judgement arms the best way to do closed bolt semi auto without extensive lathing would be to have seperate pneumatics that handle cocking.
look at paintball diagrams... they basically have most of the good open bolt and closed bolt systems already figured out...

[judgment_arms]

Yes, I know, but I thank you anyways, I was talking about inline and cheap, like the open bolt this thread’s about. I haven’t gotten around to looking in to the closed bolt system, bean content with the closed bolt. But when I mod my big gun I’m thinking of putting a pneumatically actuated breach, giving it the capability of automatic fire, that would have to use a closed bolt.

[Scope]

as long as the breach is closed when the air is released, lab test show little differation between the accuracy between open and closed bolt systems. This atleast is the verdict in paintball. The main difference is in an open bolt system you have moving mass before the shot is made. This makes the gun move before the shot leavesthe barrel

[judgment_arms]

I do not mean to offend you, my friend, but I already know this. The closed bolt system is slower than the open bolt, it’s used on guns like the B.A.R. where accuracy and range can be pull out of the big 30-06 cartridge. The closed bolt system is used on guns like the Thompson Sub Machine Gun, where the 45APC doesn’t have the accuracy nor the range of the rifle round, giving it a higher ROF.