All Springer/NP/PCP Air Gun Discussion General > Scopes And Optics Gate

Diana Bullseye ZR mount O ring placement

(1/5) > >>

I bought one of these version 2 mounts several years ago. I recently started using it. It is very tight and I cannot detect any wiggle visually. I have it mounted on a D54. I just noticed that it had 2 O-rings on the sliders but at the end that would never get any impact. I also detected that there was a metal to metal sound when the scope was moved from stop and returned to rest. I couldn't see how this was protecting the scope.
I just installed two thin O-rings on each post at the impact end. After some shooting it started making the sound again so installed one more O-ring on each end. After the last O-ring install I backed off the center set screw slightly as I wasn't sure how detrimental this conical screw was to keeping the moving mass centered. Is dampening the action correct or should I let it slam metal to metal?
Accuracy is good and currently I get one hole groups at 25 yrds when I do my part. I am just trying to save this scope from being sent in for another repair after being thrashed on the UTG DN T06 mount.


If  you have the time, read these two articles:

The essence of the system is that the mount "floats" the scope while the shot/recoil cycle is going on. There is NO "dampening" per se. The mount just "floats" the scope/

The front cone is ONE of the points that define a plane where the scope sits; THREE points in space define a plane, the other two are the ends of the steel rails.  If you prevent this cone from making solid contact, then the scope may not "register back to zero" as it should.
With usage you will see that the cone  and the base "mate" themselves to each other. Which means that a ZR mount takes some time to "settle down", IMHE, about 200 shots.

The Orings are supposed to be at the back, and they are there to measure how much travel the moving section takes in YOUR gun.
Well tuned guns will back between 3/16" and 5/16" depending on the power level. If your piston is slamming, then the mount will recoil more than the 5/16"
Just move them manually forward before shooting a 5 shot string and register/measure after shooting. Note this measurement and when in doubt, re-measure again.

Scopes are DESIGNED for the recoil of firearms, means that shocks going backwards, usually are protected from. The end of the stroke is when some airguns recoil FORWARDS, and that is when the ZR mounts have the scope floating. SO the scope is isolated from the forward recoil and reaching the rearwards end will not hurt the scope.

The other aspect is that airguns vibrate a LOT, and those vibrations tend to loosen stuff everywhere, the inside of the scope included!
Once things are loose they will start breaking by bouncing around.

So, if you want to allow the mount to do what it was designed to do, then remove the "dampening" elements and let the scope go back on the impulse of the return spring in the mount that is just a fraction of the energy of the first, backwards, recoil of the  rifle.

HTH, keep well and shoot straight!


Steven, Hector is the unchallenged expert on these mounts.  I had the metal to metal sound on my ZR mount, too.  I disassembled my mount making careful note what parts went where.  I then cleaned the rails and rubbed in a bit of molybdenum disulfide powder on each rail.  The metal to metal sound disappeared on reassembly.  Of course break in may achieve the same effect.  By the way, the stop screw is not necessary as the gun is only recoiling against the low mass of the base mount not the mass of the scope.

Thank you for the information.
I'll remove the O-rings I recently installed.
I was being overly cautious.

I removed the O-rings I installed and after shooting about 100 pellets today the travel is right at 5/16 inch.
This rifle had a recent ARH breech seal replacement, VRT spring kit installed and Tesla piston seal replacement. FPS is 770's with ES of 11 FPS.
I'll get over the metal to metal sound. I actually only hear it when I manually move the scope and let it go. The conical screw head does have a bare metal wear mark now.


[0] Message Index

[#] Next page

Go to full version
Powered by SMFPacks Media Embedder
Powered by SMFPacks Alerts Pro Mod
Powered by SMFPacks Ads Manager Mod