Ok, so I'm going to buy a pistol and SBR it or just buy a straight up SBR. I'm going piston because well I'm lazy, I shoot suppressed , I'm tired of cleaning for two days after going to the range, and no more gas face. So, what makes a short stroke(Sig, H&K, Leitner Wise) better than a long stroke (PWS)? Or do I have it completely ass backwards again? Thanks in advance.

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What I've gathered from reading is Long Stroke is more reliable, durable, etc. But with Long Stroke systems, you loose even more compatibility with standard AR15 Milspec components. Short stroke will give you more aftermarket options (rails/handguards, receivers, etc) but sacrifice some of the durability and reliability that comes with Long Stroke.

Please, correct me if I'm wrong, I am just relaying what I've read about the two.


Currenlty, I have 3 AR's, 2 of them are Adams Arms Short Stroke pistons, 1 is a Syrac Ordinance Short Stroke Piston. I like them both pretty equally, but the Syrac system is a fair amount lighter, and will fit under more handguards than the AA.

i just read about the Armalite M15 piston, its long stroke, supposed to be even more reliable than short stroke, and great for suppressed.

been thinking of a bullpup...mmm


heres the article http://www.tactical-life.com/firearms/gun-test-armalite-m-15-piston/#m-15-swmp-a15-field

I personally like the simplicity of the short-stroke piston.  I also know that if the world goes (further) to $#!+ I could return to DI should a broken SS piston gun need that to be made operational again.  

The LS units are fine pieces, but there aren't many out there, the parts are proprietary, and not everyone carries them.  I have AA pistons on everything I own, and they are all dead-nuts reliable.

What I'd really like to see is an AR LS system designed to directly utilize the AK piston.  Then it would be quite easy to find parts, and cheap to replace them if you had issues.  It would require a design to work around the standard AR upper, but I think it would be possible.  Can you say "best of both worlds?"

PWS claim that their long stroke offers lighter recoil impulse as well as reduced/eliminated carrier bolt tilt and therefore its related issues.

From what I have read, the H&K G36 /416/ MR556 short stroke piston design is one of the most reliable systems available anywhere.

I have seen some pretty insane torture tests done on these guns and can't imagine someone calling them unreliable.

I also remember reading about the "dust test" results from 2007 and I believe that the Scar, 416 & XM8 all performed significantly better than the M4 did.  So I guess reliability is relative to what you are comparing it too.  If comparing to DI then I would say that a well engineered and built piston system is extremely reliable.

I also think that a very good point was made earlier about long stroke piston gun compatibility with parts that would be readily available if the gun were to have a part breakage.

I am willing to bet that you would have more reliability issues as a result of magazine problems than you would between Long vs Short stroke piston system differences.

They claim the truth. With their adjustable gas system you can dial it down to an incredibly soft shooting gun.  Much more so than my Sig 516 or PWS.

Awesome response guys I really appreciate it. Now to throw another pickle in the punch I started looking at the MCX! I'm screwed. I just need to buy three guns!

PWS system is the best I have tried. My Diable MK107 is the only 100% reliable short upper I have ever tried.
Ran reliably out of the box with ANY ammo I have tried. From Tula, to Wold to mil-spec!

I have tried 4 to 5 different Piston ARs but so far the best long stroke upper I have run is the ARAK-21 (not to say any of the others are bad). It is nice, but comes at a cost ($1200 to start).

The Armalite piston system is made by PWS.

I came into one of the TNW piston kits a few years ago to tinker with. It worked really well. Just wasn't compatible with a lot of handgun rds and rails. Took it off.

The OP question was "Short stroke or Long stroke Piston"?

The replies have been interesting but no one has even come close to the answer, which actually is... "it depends".

Big hint right there.

I'm a skeptic from a physics point of view and I don't think it matters or changes a thing.  Both reciprocate the same mass over roughly the same distance.