"Threadlock" type stuff for pins?

I just got a used Taurus PT99 off of Gunbroker, and took it to the range today. Shoots great, no problems whatsoever. But..... I only put 50 rounds through it today, I was cleaning it after and I noticed that the pin that holds the rear sight on drifted out slightly, enough to notice. I knocked it back in, but I was wondering what I could do to keep this from happening, short of a dab of superglue on either side. It's a solid pin, not a rolled one that I could spread tighter. On Numrich the part is listed as "rear sight pin" no dimensions listed.

Blue loctite.

Just make sure the loc tite is marked as re-workable or serviceable. The permanent stuff could be a problem if you need to get the pin out later. I'm also a fan of clear fingernail polish. It's sticky enough to hold but not too much trouble to remove.

Thankya!