Comments on Primary Weapons Systems (PWS) and its long-stroke piston?

[Jaywalker]

I can't find anything of note in P-F with regard to PWS's long-stroke piston models. (Generally, when I can't find something on P-F I take it to mean "It's not worth talking about," but the PWS comments I find elsewhere are pretty uniformly positive, so I thought I'd ask.)

I've pretty much decided to make a strong effort to reduce the noise and blast effect of rifle/carbine by moving to 100% suppressor shooting. I think I'd rather have a separate carbine for this, preferably one that I can keep a little cleaner than a suppressed standard direct impingement carbine. I'm considering an AK variant, so why not consider a piston AR? In a piston AR I want a company that will be around awhile as I'll be tied to their proprietary product, a carbine that's reliable and reasonably accurate and easy to suppress. Cost is an issue, but less so than the first three requirements. I understand the AK is more reliable with its long-stroke piston than the SKS and its short-stroke, so if that doesn't hold true in the AR world I'd like to know.

I'm also considering LWRCi but I've I've been able to find data on them, so in this thread I'd like to learn about PWS. Please tell me what you think I should know.

[WobblyPossum]

Aaron Cowan is a fan of PWS. He partnered with them to release a Sage Dynamics edition rifle. He’s since partnered with SOLGW for a Sage Dynamics gun but said in a recent video that he still very much liked the PWS guns.

[Suvorov]

I have a MK216 and I absolutely LOVE it! Other than a few ammo related issues early on it has been 100% reliable with just over 2000 rounds down the pipe. I've shot sub MOA 5-round groups with it out to 300 yards (and some bigger) so I would say it is right around a 1 MOA rifle. Had one issue with the bolt catch plunger seizing up on me and I stripped the screw that held the bolt catch in place which required a return trip to the factory, turn around was quick.

As far as shooting goes, it is a nice shooting rifle with a very smooth recoil impulse. Hard for me to know how much of the recoil is tamed by the brake and how much by the gas system but it is every bit as soft shooting as my M1A. Really just an enjoyable and accurate .308 rifle that you can shoot all day.

I haven't ever had the opportunity to run it suppressed so can't offer anything on that.

I don't have any experience with their 5.56 offerings but given my experience with the 216 they would be my first stop if I was in the market for a piston driven AR in 556. My primary AR is a SIG516 which uses a short stroke piston configuration similar to the LWRC and HK416. It's been super reliable as well with more rounds through it that my PWS. It's hard for me to determine which system is more reliable, my gut tells me that both are on par with each other. The PWS operating rod is two parts like the AK but it is far less robust than the AK being similar in diameter to gas tube on an AR and the two pieces fit together rather than are pinned like the AK . The one advantage I see with the long stroke over the short stroke is the recoil impulse as the PWS vents the gas in a metered fashion (explained in their videos) while my 516 has a fairly sharp impulse (then again I am comparing a 762N gun to a 556 gun). There are also a few less parts in the PWS gas system than the 516s so that might also be better?

ETA - and yeah, the Slavophile in me smiles to know that inside of my AR is the the heart of an AK.

[Default.mp3]

I did not notice my PWS MK110 Mod 1 being any cleaner than my DI AR-15s when suppressed, though all my AR-15s that I shoot often are tuned for suppressed shooting. Even with the suppressed setting on the gas block, it was severely overgassed when using a SureFire SOCOM556-RC (it was able to feed PMC Bronze on position 3 of 4 of the gas block even without a suppressor, despite position 3 being nominally for suppressed .223 Rem use, while used in conjunction with a Sprinco green spring and a Slash XH 10 oz A5 buffer). I never really shot it for groups, but I remember accuracy being acceptable with Gold Dot. Bolt lugs sheared at ~2200 rounds shot.

PWS customer service was always excellent and responsive. They replaced my bolt for free, and also replaced the gas block adjustment so that the gun would be less overgassed, which actually led to it being undergassed for unsuppressed shooting, which they also rectified. However, I still found my tuned DI guns to be more pleasant to shoot suppressed in terms of gas-to-face.

I would suggest simply building or modifying a DI gun tuned for use with your suppressor, rather than messing with a piston gun, for the sake of commonality of parts and staying out of a proprietary ecosystem. My PWS gun was very nice, but ultimately I did not see any advantage offered by it. Alternatively, there are starting to be much more low backpressure cans becoming available, so you could pick up one of those and use them with your existing DI guns without modification.

[LukeNCMX]

Unpopular opinion i’m sure, but I never understood piston ARs outside of austere environments with a suppresor.

Run a light grease instead of oil, wear eye pro, and use one of the numerous charging handles with a gas deflector.

Also, take the time to time to setup a proper buffer weight that can run suppressed or unsuppressed.

The weight and balance benefits of a DI gun alone are 100% worth the increased cleaning frequency.

My Mark 18/socom mini/A5H4 runs like an absolute dream.

[Jaywalker]

However, I still found my tuned DI guns to be more pleasant to shoot suppressed in terms of gas-to-face.

Did the gas-to-face come out the back of the receiver or the ejection port? This was the standard charging handle supplied by PWS?

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Did the gas-to-face come out the back of the receiver or the ejection port? This was the standard charging handle supplied by PWS?

Back of the receiver. This was with a standard AXTS Raptor, the Freedom Bone (now the Raptor SD), and the Geissele SCH.

[Jaywalker]

Back of the receiver. This was with a standard AXTS Raptor, the Freedom Bone (now the Raptor SD), and the Geissele SCH.

They're putting the Raptor on the MK116 MOD 2-M now, I understand.

[snow white]

I've owned a pws for some time now and have used it in many classes. I really love mine and it has proven to be 100% reliable for me. It's definitely a bit heavy compared to a DI gun of the same size but boy is it nice with a can.

[crosseyedshooter]

I shoot left-handed so I really went looking for less gas blowback with a suppressed AR. I have the latest iteration of the Mk111 Mod 2 upper with the three-position gas block. Paired with a Sandman K, it’s very pleasant for me to shoot but there’s definitely a little puff of gas coming back down the barrel and out the ejection port. The weight and balance feels similar to a medium contour barrel DI upper. One thing to keep in mind is PWS doesn’t sell the special barrel nut wrench needed to fully service the upper and pretty much every part is proprietary. This upper will only last as long as the company.