Oh I used the right stuff per the manufacturer and thank god I keep RMR extra screws. I’ve gone from pistols, pistols with plates, trijicon co-witness AR mounts, MP5s and now on a PS90 and never had one strip out like this. But I think it was a combination of soft screw head/torx, a bit heavy handed on the blue on my part, and that was unnecessary being on a PS90 mount that doesn’t reciprocate like a handgun does. No loctite this time. Fresh battery, 15 in/lbs and paint marker it is