Being a trap shooter, I'll go along with Jerry's suggestion, Shooters Choice grease. It comes in a plastic syringe and I
use it when I take a lock completely apart. I will use it on the tumber hole, place some on the top of the sear where the
sear spring rides against it, and on the tumbler where the main spring hits it....seems to work great. I also have some
fine oil that I use elsewhere on any moveable part to keep them lubed. I too have seen locks that apparently never
received any oil....very disturbing. That lock is just like a little machine in there, keep it oiled.........Don