I've learned that the first thing that I must do to a new revolver before using it is to hose it out really good through the hammer and trigger openings with Gunscrubber, then blow it out with my air compressor, then hose it out really good again with Breakfree, and then blow out all the excess oil with the air compressor again.
This gets all of the factory crud out of the action and makes the trigger much more consistent.
Some autos, like SIGS and, of course, Glocks, have synthetic parts inside that the solvent might be too harsh for - so be careful!.
Gunscrubber makes a plastic-safe solvent, but I have not tried it yet.