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  • PWS Pro upper (mini review in comments)

     Luna updated 10 months, 1 week ago 2 Members · 2 Posts
  • Luna

    December 16, 2019 at 7:50 pm

    PWS Pro upper (mini review in comments)

  • modena1983

    December 16, 2019 at 7:50 pm

    So, I figured I would take the time to do an initial impression of this upper receiver group, since I did not see a whole lot of info out there regarding these. 

    I purchased the PWS mk111 pro upper receiver group. This is Primary Weapons Systems’ lowest end model. However, according to company literature, it still had the same internal components of the higher end models. The cost savings comes from purchasing the same parts in larger batches and using an extruded 6061 upper receiver. It features an 11.85 inch barrel and carbine length gas system and a 223 Wylde chambering.

    My background:

    I’ve built 5 rifles and help build 5-6 others in various calibers/lengths. I have some experience with a friend’s osprey short stroke piston converted rifle. I’ve done some training with a former Marine and taken a carbine course. I’m by no means an expert. Just a guy who enjoys building rifles and who enjoys the platform.


    Initial impressions:

    The handguard looked really good – nice and slim. It feels really nice as far as profile, rigidity and machining.

    Initially, I thought I got a defective upper. I tried it on several of my lowers and I could not pull the charging handle back more than half an inch, or so. It turns out that the thicker walled upper receiver keeps the maritime bolt catch constantly engaged. Once I tried it on a friend’s lower with a Milspec catch, it worked just fine. Primary Weapons Systems have a bolded blurb on their website regarding this now, but I did not see it when I initially researched these when they were released. This is really my only negative regarding the product.

    I ran 150 rounds through it (I know not many, that’s why it’s just an initial impression) and it ran flawlessly. I averaged 1.3 moa groups with M193 ammunition, running Iron sights and a milspec trigger.


    The recoil sensation is a bit harsher than my other rifles/pistols; however, they all have muzzle brakes and are nicely gassed. I would compare the amount of recoil to an over gassed carbine length gas system that has a buffer that is to light. I ran it with an H2 buffer. I believe, with a VG6 gamma installed, it would be similar to my DI guns. It would have maybe 10% more recoil than a similarly gassed upper with the same gas length. Again all of my DI guns shoot supernaturally soft so take this part with a grain of salt. Yes I know 5.56 does not have much recoil to begin with, just pointing it out because I see people ask about it.

    Features I liked:

    The upper receiver is slotted so that the handguard slides into it (at the top as a part of the 1913 rail) like the 416 and some other designs. Obviously it is impossible to rotate (I’ve had a handguard rotate, so I appreciate this design feature). That is another feature that should be more common IMO, though I understand why it’s not. 

    The gas block journal has a slot, so the gas block aligns perfectly . I do not know why this is not more common. The gas block also appears to be secured with something akin to a castle nut, again another great feature.


    I think the progressive gas venting is a worthwhile upgrade over standard venting, but again is just my opinion.


    I liked the fitment. This upper receiver group fits extremely tight on all of my aero lowers. It is tight enough that there is no slop. Even when installed on my friend’s lower, it felt solid with no rattle/play. 

    I think the thicker walled upper benefits accuracy, but I do not have a test or data to back this up. The thicker wall may be to compensate for the reduction in stiffness that may come with using an extrusion or the type of aluminum used(6061). I could not tell you if either one of those two things make the upper less rigid than a 7075 forged upper. I am just spit-balling here. Feel free to correct me if I’m wrong (I probably am).


    Sadly, I forgot to play with the adjustable gas system, so I don’t have anything to report there. It does have 3 adjustment positions.



    I was astounded with the accuracy out of M193 ammunition and really like the fit and feel of the upper receiver group. Even though I purchased the lower end model I appreciate the well-thought-out upgrades. Based on my limited shooting, Primary Weapons Systems are definitely doing things right. I will definitely be buying another, either a mk1, mod1 or mod2 in the 14.5 inch barrel length. The PWS mk111 pro upper receiver group is definitely a really solid “Go-To” option as far as Rifles go.

  • ShowLoveUpstate

    December 16, 2019 at 7:50 pm

    Love the grip who makes it?

  • R3D1G18

    December 16, 2019 at 7:50 pm

    I got the same setup (but with their lower) have you tried running hornady frontier 62gr through it yet? If not you should definitely look into it, my MK111 loves it!

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