Originally Posted by
LRRPF52
This was already explained in great detail to you here in the thread. The Stoner bolt tail is a static piston, and does in fact act on the carrier by sealing the chamber with the gas rings, causing the gas to expand in the chamber.
Think of it as a piston that throws the housing, like the syringe example. From the patent of one of the greatest firearms engineers in history again:
Doubling down on the idea that the Stoner system does not have a piston is in direct contrast to what the patent states, and what the bolt actually does in reality. It is a stationary piston. The Ljungman Direct Impingement has no piston at all. This is why the AR15 is not DI, and the Ljungman is. If this were a court case, it would be very easy for me to win a ruling by simply reading the patent aloud.
Stoner and his aerospace engineering team at ArmaLite were not ignoramuses, and they had over a dozen previous firearms designs alone in house they had worked on, many of which are still in use today. (AR-7, AR-10, AR-18...)
If this is simply a personal issue where one feels a need to double down on the incorrect definition we were all plagued with before we could read the patent (guilty myself), then I understand, but digging in one's heels on this isn't going to help any. The only real solution is to admit being wrong, move forward, and accept what is said in the patents.
When I first heard the Stoner system wasn't DI, I was ready to jump down someone's throat and correct them, but then I noticed this little link to the patents, which I took the time to read and then realized we had been calling this the wrong thing all these years. A lazy person who looked at the Ljungman probably associated the AR10/15 with it, then said, "It's like the Ag m/42 Ljungman direct impingement system." And gun people called it that ever since.
We were simply wrong.