Head's up for other owners!
SHould you knock the "C" Clip that retqains the cocking lever pivot Pin loose (Or off into never-never land as I did...) Please note that aftermarket "C Clips" aren't shaped as elongated as an RWS origonal is. You need to take extra care when trying to snap the replacement in place!
I found that backing-up the replacement Clip (from the underside) using either a thin , flat screwdriver or better yet a good pin punch, makes the task of keeping the opening centered over the "Locking Groove". Mine took 45 minutes of playing around to get the snapring engaged!
Secondly, do not try to squeeze the outside wings(Right Name?) tightlly over the "C Clip". You will only cause the Clip to rotate and pop off again. Best to leave the Clip able to rotate as you cock the action.
We learn by our mistakes and I hope my mistake here will save you all some grief!
On another topic: (Experience speakinmg...) The inexpensive Gamo Droop Adjustable Scope Mounts work VERY well on the BIG Model 40! Mine holds a 3x12x40 BSA A/ scope rock steady However, if you forget to check tightness on the droop compensation system occasionally, you will find that it "CAN" be shaken loose (even with a mild mannered JM GSI Mainspring and even with an ample JM "Thick Tar" Coating on the Spring. Use a light coat of "lock-Tite" on all threads. HE-HE, Glad Gamo stuff is cheap. I bought three just in case I had a future failure!
DO re-checks on your allen bolts every 500 shots. RE-do the Lock-Tite as needed.
Enjoy the Big Magums! Shoot em LOTS and LOTS!!!
Just pay close attention to even minor POI shifts, as they may indicate a mount working itself loose, OK?
One more hint: The Leapers Med and High mounts have a nice detent pin on the rear mount! Fits HW and several Beeman Recievers well!
Be safe
ZVP Forum Owner.