I have a RMR type 2 mounted on a glock 19 gen 4. I noticed that one of my screws came loose. Maybe 1/8 to 1/4 turn from my witness mark. If I remove the 1 screw and replace it and put some more blue locktite on it, will that mess up my zero? As of now it's spot on and I have not problem re-zerioing it, but wanted double check before doing. This is the only time I have had a screw come loose. I had to replace the battery which I rezeroed afterward, but wasn't sure if that would be required for just a screw.

Thanks,

Billy

Is the other one tight?
If so it should be ok to retighten

It should be fine, or really close. Even taking it off to replace the battery isn’t going to cause a large zero shift.

Make sure you clean and degrease everything before adding new loctite and reinstalling.  Also make sure you are using a torque driver to torque the screws to the appropriate specs and then don’t shoot the gun for 24 hours to allow time for the loctite to set.