If there are those on the forum new to firearm maintenance, please consider using a very tiny drop when inserting oil into the firing pin hole, and then wipe away the excess.
I am reminded of this because the firing pin hole is one of the maintenance points for the R9.
Time and again, over the years, I've been warned about oil contaminating the primer, which may result in a round which will not fire.
Some people even seal the primer so it will remain fresh when carried in the chamber. The well-known Texas pistolsmith, Teddy Jacobson, advocates primer sealing. http://www.actionsbyt.com/
That's going a little far, but I try hard to keep oil away from the cartridge.
My apologies for preaching to the choir.