Blowback design is gas driven
I’m also saying gas driven but the flow chart says gas operated. PCCs are gas operated.
Blowback uses the force of the barrel and or chamber pushing back on the bolt/carrier?blowback uses the physical force of the barrel/chamber pushing back on the bolt/carrier. In a short recoil the barrel travels a short distance, unlocks from the bolt/carrier, and the bolt continues on it's own inertia. In a long recoil the barrel and bolt travel all the way back together then the barrel is released to return forward while the bolt is held back with the shell casing. The shell is ejected and when the barrel seats the bolt is then released to travel forward. Some smaller calipers do use a fixed non-locking barrel but there are limits because the weight of the bolt is all that is delaying its rearward movement. Anything more then a 380acp gets dicey.
In a gas operated there is a gas hole in the barrel and the gas is used to push the bolt back, the barrel is fixed in place. With direct impingement the gas itself pushed on the bolt, in a piston operated gun the gus pushes the piston and the piston pushed the both. The barrel is locked in place in both of these.
I thought the result of the expanding gas pushed the action back.
The barrel and chamber isn’t pushing on anything in a blowback system. A blowback system is gas operated any way you look at it.