"Trigger Job" is a loose term. For technical work, I also use a hard stone for metal removal and polishing, but sometimes use my wife's fingernail buff pads for polishing. Another factor is the spring which loads the hammer. Sometimes, removing a coil will go a long way to lightening the pull, but may result in too light of a primer strike to reliablbly ignite the primer. If you are talking about a Ruger Black Hawk, lifting one of the spring legs of the mousetrap spring off of the grip frame will lighten the pull considerably. Years back, in another life, I had the fortune to attend the Beretta's Armorer's Course. The instructor was an old Danish gent whose name will remain unsaid. He related when he had his own shop and someone came in wanting a trigger job, he made a big deal of logging the pistol in and telling the customer to come back in two weeks. In the meantime, he would put positive pressure on the hammer, pull the trigger and repeat a few times. He was force wearing the hammer and sear to give a better pull.