Nikon no longer makes scopesIMHO....contact the manufacturer.
I once had a "cheap scope" from a very popular brand. When I bought it USED, it was missing a turret cap.
So, I was looking for a replacement turret cap for quite a while. Checking at various gun stores throughout the years (when I remembered about it). It was a long while before I finally got encouraged to try contacting the manufacturer.
I was told by the manufacturer that......
They no longer carried caps for that particular model, as it was a foreign-made product and they have since changed their source for the scope.
Yeah.....apparently the thread pitch had changed from one batch (Import Manufacturer) to the next.
PS.......as for NIKON? Who knows. IMHO, just save yourself and contact the manufacturer.