So, I just got done at the range, where I fired 200 rounds. When I got done, I was policing my brass and noticed a screw amongst the brass.
The screw came from my optic. One screw had come out, and the other one was loose. Is this more likely to be a bad design (where I need a new optic), or bad screw lock (where I need to clean the screws and reapply screw lock)?
Loctite 242. SOP on rails and attachments imo,pretty much anything with a screw. I even do my grips, as they’ve backed out.
If it has a screw, it gets the blue.
Medium strength thread locker pretty much belongs on everything threaded that attaches to a firearm, unless explicitly otherwise stated by the manufacturer
Oh, and I also have become a strong believer of using a torque wrench to torque to spec. Wheeler engineering or Vortex are the two go-to
Well, the screws did have the blue, but it was on there from the factory. I suppose I’ll need to clean the screws and reapply. Thank you.
Bad screw lock.
It happened with plate in my new Staccato C2. I noticed my plate to be loose after 2 hrs shooting (I have no idea how many rds).
I used Loctite 242 and the problem had gone.
I’m far away from stating that it might be a bad design… 
Blue Loctite works ONLY when both surfaces are clean and degreased. If you are not sure is you clean it enough, use Loctite 243 which is upgraded version of 242 and it’s oil resistant.
I used to go with Loctite blue. Screws would eventually loosen and come out; I usually would notice it when my hits on the target were about 4 inches off…I’d check the optic and it was loose. Once one of the screws was on the range floor. I’ve since switched to VC-3. Clean the screws, apply, let dry for a bit, then screw them down as usual. They recommend applying an oil based marker to the bottom side of the the screw head prior to doing this. I’ve done this on a Glock and Walther and both no longer have loose screws; it’s been about 1000 rds for the Walther and maybe 500 for the Glock: no issues at all.
https://www.vibra-tite.com/threadlockers/removable-reusable-threadlockers/vibra-tite-vc-3-threadmate/
Part of my range prep is screw tightening. It’s just a habit. There are certain fasteners on each gun that I know will be loose. I guess I could go the Loctite route but so far maintenance seems to be working.
Every screw in your rig needs thread locker that includes your belt, holster, etc.
After torquing anything, I apply two micro dots of white enamel - one to the edge of the screw or bolt head and one on the frame (so they sit side by side). A quick glance tells me if there is any losening problem. Pens available at arts & crafts or hobby stores. Hint: try to avoid removing the dots when cleaning.
Witness marks are a great thing. Good add.
I use red nail polish.
From the title, I thought this thread was about Joe Biden.
Take what I’m about to say with a grain of salt. I don’t run optics on handguns.
What gun? I’ve heard this is somewhat common with guns like the Glock MOS with mounting plates that are not cut for a specific optic. Apparently the Mount can shake too much if the Mount is not a perfect snug fit.
Thread locker won’t help tighten those screws unfortunately
I didn’t say anything about making screws tighter (applying more torque).