Odd problem with Leupold Mark AR and Warne QD Rings
I'd previously posted this on another forum, but thought it would be of interest here too.
I noticed that the 4-12X Leupold Mark AR I have on my Mini-14 Target Model exhibited signs of internal binding on the zoom ring when I tightened the Warne QD rings past about 16 In/Lbs using a calibrated Wiha Torque Wrench Driver. Leupold told me it was because the QD Rings with the vertical split tightened differently from regular rings, so I rotated the scope 90 degrees (windage turret up) and tightened to normal 25 In/Lbs per spec. Same problem only it didn't get better when I let the torque off, so I sent the scope back for repair. I had more communication with Leupold and they said that rotating the scope had nothing to do with the issue, it was the way the rings tightened.
I was suspicions of what I'd heard from Leupold, and contacted Warne for their take on it. Warne verified that some individual Scopes will exhibit this problem. Apparently the Warne Rings really do tighten up differently in that you tighten the bottom gap closed first, then set the torque on the top set of screws. Not like regular rings where one would try to keep the same gap on both sides of the rings. Anyway if there is an individual scope with real tight internal tolerances the Warne Rings close can cause binding on the zoom ring. This from Warne themselves. They claim the problem is rare and if one has a scope exhibiting the problem, to tighten the front set of rings up to 26-28 In/Lbs and only tighten the back rings to 15 In/Lbs. They said loosening under recoil shouldn't be a problem with .223 or 5.56, although with hard kicking rifle it might.