I just ordered and received one of these from Uncompany.
http://www.uncompany.com/pageproduct...p?prodid=29681
So far, I have puty about 300 rounds through it on my open bolt NPAS WE PDW and it looks to be holding zero just fine. Don't forget, windage and elevation for elcan scopes is an adjustment of the mount, not an adjustment of the crosshairs, so unless there is something seriously wrong with your scope & mount, there is little chance you'll have trouble holding zero.
What I have noticed so far -
-The front iron sight is loose. It came to me in that condition.
-The battery cover is retained with a simple piece of thread - I'll have to rectify that with some wire of some sort.
-The QR tabs seemed to hold the scope a wee bit loose on my gun - This was cured by slightly bending the steel pressure tabs.
-There is a slight bit of play in the mount itself, however this play is self-centering so its not really an issue.
-The scope comes with a spare set of iron sights & screws, & an extra battery.
-The crosshairs are nice and sharp, and aren't magnified when you set the scope to 4x
-The red/green dot shares registration. Both colors provide 5 distinct illumination levels.
-When transitioning from 1x to 4x the scope does actually zoom, however the sight picture is slightly defocussed during transition.
-Scope image quality is excellent - sharp at both 1x and 4x
-Scope finish is basic flat black with sharply laser etched trades and markings.
-The scope doesn't seem to be airtight & threfore it is unlikely that it is nitrogen purged & unlikely to be waterproof
-I don't think a killflash will fit - There is only one or two threads visible at the muzzle end of the scope and they are gunked up with some kind of sealant/adhesive
-Eye relief is 2-3 or 4 inches... it shouldn't hit your goggles.
-Unlike a red-dot, you are still looking through an optic when it is set to 1x, so you will get tunnel vision if you try to look through the scope from further than 4 inches.