My experience with my ROCK and the Holoson HS507K-X2 is as follows.
The first time I trimmed the mounting screws I did not have the dimensions mentioned here at my shop where I shortened my mounting screws. I just stuck my caliper in the mounting hole and made some quick measurements then shortened the screws on a fine bench grinder. Everything seemed fine until I tried to disassemble the slide to thoroughly clean it. I was unable to tap the striker shells out of the slide, they should tap out fairly easily. I had to remove the Holosun to get the striker shells out because the screws were still too long and were contacting the striker shells.
Anyway here are the measurements that I finally arrived at that worked for me.
My mounting screws ended up being just over 9.5 mm long. Any longer than 9.5 mm and they will just protrude through the threaded hole in the slide and possibly contact your striker shells.
The thickness of my Holosun mounting base is 7.1 mm So in my case trimming the screws to 7.1 mm would have resulted in them sticking through my Holosuns base roughly .2 mm Not nearly long enough to attach the optic properly. The mounting screws sit slightly recessed in the Holosun mounting base.
4 Likes