I’m starting this thread to keep from further derailing another.
When this was posted in another thread-
I responded with-
Which inspired-
(Very astute. Too often I am one of those wise guys)
Everybody up to speed? Good.
To answer TSH’s last question, the tail of the bolt is the piston, complete with rings
If the rings are missing, damaged or worn, the rifle will not function. The bolt is the piston, the carrier is the cylinder. DI systems do not use rings, nor do they use an expansion chamber as the AR does. With a DI system, the gases impinge directly on the bolt carrier. If the AR gas key was just a cup, the AR would be a DI system. Instead, it’s a tube guiding the gas into a cylinder.
This thread isn’t about “DI vs Piston ARs”. It’s to clarify the fact that the AR has a piston and is not really a DI system.
This site is known to not accept simply regurgitating what others have posted on the internet. We are encouraged to do our own research and become our own Subject Matter Expert. I did my own research and discovered the AR isn’t a DI system as is being often repeated. Don’t take my word for it, do your own research of the AR, Ljungman and other operating systems and come to your own conclusions
I believe this below is a “true” DI system within a rifle, but since the AR’s gas system is a hybrid of the DI and Piston systems should it have its own name, i.e. the Stoner Impingement Expansion Chamber Piston (sans rod) System or is there an accurate engineering term for the system that exists?
Is it important to differentiate between the the DI and the Stoner System this late in the game? It would take alot of reeducating and was wondering if there was anything to be gained or is it just for empirical clarification to give credit where credit is due for a unique system that is mislabeled as something inferior?
I enjoyed the post and like to see the clarity of facts, but was wondering if you were headed somewhere with it…
Knowing the difference has given me a better understanding of how the AR (and other rifles) work and has lead me to asking and finding the answers to other questions. I also feel it will give folks a better understanding when discussing so-called “piston” uppers and when comparing the AR to other designs
From the patent (transcribed by me):
[b][i]
"It is a principal object of this invention to utilize the basic parts of an automatic rifle mechanism such as the bolt and bolt carrier to perform a double function. This double function consist of the bolt’s primary function to lock the breech against the pressure of firing, and secondarily, to act as a stationary piston to actuate the automatic rifle mechanism. The primary function of the bolt carrier is to lock and unlock the bolt by rotating it and to carry it back and forth in the receiver. The secondary function of the bolt carrier is to act as a moveable cylinder to actuate the automatic rifle mechanism. By having the bolt carrier act as a moveable cylinder and the bolt act as a stationary piston, the need for conventional gas cylinder, piston and actuating rod assembly is eliminated.
It is an object of this invention to provide a gas system which is lighter and less expensive to produce because of its simplicity than the present gas system now used in automatic rifle mechanisms.
It is another object of this invention to utilize the energy of the expanding gas developed by the firing of the weapon for the actuating of the automatic rifle mechanism directly by use of a metered amount of gas coming from the barrel. This invention is a true expanding gas system instead of the conventional impinging gas system. By utilization of a metered amount of gas from the barrel, the automatic rifle mechanism is less sensitive to different firing pressures caused by variations in the propelling charge. It is therefore still another object of this invention, to provide a rifle mechanism which is not affected by variations in the propelling charge.
A further object of this invention is to provide smoother operation and longer life of the working parts of the automatic rifle mechanism. Since, in this invention, the actuating force is transmitted directly down the centerline of the barrel and the bolt mechanism to the shoulder of the shooter, all of the off center loads found in most other types of gas actuated weapons are eliminated."[/i][/b]
Mr. Stoner was a f*cking genius with his piston gun.
There, I did the bitch work for the forum.
I don’t think Mist is trying to get people change what they call the AR system, but the very name is akin to the media calling it an “assault rifle”. In the context of discussing piston AR models, maybe some people will realize that they have un-engineered and re-incorporated what Stoner took great care to remove. Further, the AR already HAS a piston, which also happens to be composed of the bolt and the carrier. Piston lovers will have their heads explode upon reading the patent text above.
I never thought of the rings on the bolt itself as piston rings. Mistwolf, you definitely have a good sense of “thinking outside the box” and now it makes sense to me. Starting this thread was a good idea.
