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Posted: 3/13/2005 3:32:29 PM EST
Okay, how exactly do they work?

Does the expanding gas completely push the bolt back on its own, and instead of the buffer spring absorbing the recoil the spring in the gas piston absorbs it?

Or

Does the gas piston only unlock the bolt and the inertia from the bullet does the rest? Kinda like an FAL.
Link Posted: 3/13/2005 3:33:44 PM EST
see: AK 47
Link Posted: 3/13/2005 3:36:47 PM EST
It uses a piston upper to operate.

Link Posted: 3/13/2005 3:38:27 PM EST
instead of gasses blowing through a tiny tube and messing the chamber i would amagine a rod pushes the bolt back
Link Posted: 3/13/2005 3:39:46 PM EST
If it ain't broke don't fix it.
Link Posted: 3/13/2005 3:40:27 PM EST
It's a solution in search of a problem.
Link Posted: 3/13/2005 3:46:57 PM EST
Anybody have time to elaborate?
Link Posted: 3/13/2005 3:47:23 PM EST
instead of gasses blowing through a tiny tube and messing the chamber i would amagine a rod pushes the bolt back

The gasses in a conventional AR-15/M16 do not blow into the chamber. They go into the bolt carrier. the rear of the bolt and the bolt carrier are the gas piston, so to speak.

Rhino made a piston upper back in the mid 80's, and no one seemed to want them. Then, as now, as 50cal said, "a solution in search of a problem".

Link Posted: 3/13/2005 5:31:25 PM EST
Im pretty much retarted when it comes to AKs and the specifics of its gas system. Please elaborate a little more.
Link Posted: 3/13/2005 8:32:35 PM EST
In each system, the gas pressure only moves the bolt carrier a short distance, perhaps 1/4 inch, before the bullet exits the muzzle. But this occurs in milliseconds, so the inertia generated carries the bolt carrier through the rest of its travel. Almost like a hammer impact.
On a standard AR the gas pushes the carrier back from the chamber behind the bolt (sealed by the gas rings.)
The piston systems have the chamber in the front sight base, pushing the gas rod to the rear to impact the carrier. Usually they have a lug where the gas key would normally be, that contacts the piston rod.
In a short stroke system like these, the piston/rod usually only travels an inch or less. An AK is a long stroke system, and the piston is attatched to the carrier.
Link Posted: 3/13/2005 8:48:14 PM EST
Why would anyone want to do this to a perfectly good ar?
Link Posted: 3/13/2005 10:45:09 PM EST

Originally Posted By chaos4570:
Why would anyone want to do this to a perfectly good ar?

Because some people think the bolt/carrier getting dirty is what causes failures. Moving the gas system closer to the port only increases the "dirt" problem becase it makes the deposits harder since the gas temperature is much greater.

I have intentionally neglected my AR in the bolt area for over 1500 rounds. Never had a failure. As Stoner designed it, it is self-cleaning. No, not "white glove" clean but functional clean. Sure, carbon builds up but only to a certain level. Once the deposits are a few mils thick on the back of the bolt, the insulating effect of the deposit limits the deposition rate to where gas velocity effectively prevents further build-up.
Link Posted: 3/13/2005 11:48:19 PM EST

Originally Posted By Keith_J:

Originally Posted By chaos4570:
Why would anyone want to do this to a perfectly good ar?

Because some people think the bolt/carrier getting dirty is what causes failures. Moving the gas system closer to the port only increases the "dirt" problem becase it makes the deposits harder since the gas temperature is much greater.

I have intentionally neglected my AR in the bolt area for over 1500 rounds. Never had a failure. As Stoner designed it, it is self-cleaning. No, not "white glove" clean but functional clean. Sure, carbon builds up but only to a certain level. Once the deposits are a few mils thick on the back of the bolt, the insulating effect of the deposit limits the deposition rate to where gas velocity effectively prevents further build-up.




i hear folks speak of how finicky AR's are. this kept me from purchasing one for the longest time. All of my ar's function properly with quality mags and good ammo.
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