I’m having an issue with a replacement HK rear sight rotary drum i recently purchased. It’s also important to note I’m attempting to install a MeproLight rear blade as well. Upon install, the cylinder still spins free without the discernible, tactile click found when adjusting apertures. I was installing the spring first, then the ball bearing. Secondly, I positioned the sight base/drum over the spring/bearing and placed the oval washer into the sight based slot, followed by the Mepro blade. Lastly, the lock washer/screw and windage screw to secure the assembly in place. This process is still allowing the drum to spin somewhat freely versus the discernible click. I spoke to HK Parts this morning who suggested the bearing go in first and then the spring which didn’t sound right but I tried this as well, with the same result. Any thoughts or recommended gurus in the metro Atlanta area? Thanks, Jason
