Long stroke VS. short stroke gas piston system?

[tvfreakarms]

What is the difference between the long and short piston system?
I believe the AK uses a long stroke system! And i've read and heard about how reliable the AK is as in durability. So, why wouldn't some of these company that make gas piston AR's use the long stroke system instead of short stroke system?[?]

[professorhard]

Addax makes long stroke gas piston AR uppers.

[$P-Ritch$]

They are getting ready to come out with their new ESS (Enhanced Short Stroke) piston system here very soon. Maybe Chris or someone else very knowledgeable will be able to chime in the pros and cons of each type.

[Addax]

What is the difference between the long and short piston system?
I believe the AK uses a long stroke system! And i've read and heard about how reliable the AK is as in durability. So, why wouldn't some of these company that make gas piston AR's use the long stroke system instead of short stroke system?[?]

You mean like this? This is a piston rod with piston from the PWS Long Stroke Piston system we use in our current line of ATAC Gas Piston Uppers.





With a long stroke system, the piston travels back further than a short stroke system, before venting out all of the gas.

The long stroke system requires some sort of long piston tube or hardware to support the piston rod. In the case of the PWS long stroke system, they developed a special trunnion, piston tube, gas block and detachable rail panels (non free float rail system) as a part of the overall piston system.



With the Long stroke systems, it is generally difficult to incorporate a free float rail properly, since the long stroke system requires a long piston tube and / or some sort of mounting hardware as seen in the picture above, to support the piston rod properly.

In terms of operation, the PWS long stroke piston system travels back as one unit (piston and bolt carrier), and since there is more mass, the actual felt recoil is softer, since you have more mass and a longer stroke absorbing a bit of the felt recoil.

With the PWS long stroke system, there are no parts hitting each other, since the piston-rod is attached directly to the bolt carrier, and this allows the PWS Long Stroke System we currently use in our ATAC GPU uppers to cycle smoothly, and still maintain a really good level of accuracy.

Most short stroke systems require around 1" or less of travel, and since a part of its travel starts within the gas block on most short stroke systems, incorporating a freefloat rail system is easier (depending on how the system is designed).

Short stroke systems normally have a piston that will impart on an op-rod which will then push a one piece bolt carrier into operation.

Since most Short Stroke system pistons normally move about 1" or less before expelling the gas, so they can be a little punchier in felt recoil over a long stroke system.

We have been working on a new piston system here at Addax that incorporates some of the operating attributes of a long stroke system, yet housed in a short stroke piston system body, and we call this the Addax ESS (Enhanced Short Stroke).

The Addax ESS system is simple, efficient, and very easy to use and operate, plus it is built like a tank, but without the excess weight.

The ESS system is designed to lengthen the amount of dwell time during operation to reduce the punchy recoil of a short stroke, and providing a softer/smoother cycle like you would feel on some long stroke piston systems. This is achieved by a specially designed gas block and piston tube, that has 4 different gas port settings.

Also, the ESS allows the user to utilize a few different hand guard, and free float rail options, and more off the shelf AR components vs. having a proprietary mounting or rail system.

We plan on going into full production after we complete our current series of tests being conducted in Alaska, and soon in Arizona.

We also still plan on carrying several of our more unique long stroke ATAC models utilizing the PWS long stroke system, that will compliment our new line of Addax Piston uppers with the Addax ESS piston system.

Addax ESS Piston System / Upper prototype pics.