The hammer stays down on all revolvers. After making sure the pistol is empty I pull the hammer back and keep my left thumb on the hammer spur and push, wiggle and torment it until I am sure it is not going to release from pressure, I then play with the trigger, wiggle it sideways and if it passes this, P.S. I always first ask the owner if I can test it, I then pull the trigger to see if it is around 3 pounds or more. Why do I do this? I've seen revolvers that exibited all the faults I just mentioned. I always test well if the screws look like thay are buggered, this means some idiot with his first screw driver has been in the lock works. As a side note, I always ensure a rifle or shotgun is empty, point it away from folks and smack the butt hard several times. I bought a used rifle one time and found it would fire sometimes from just closing the bolt. I had to fix it. Some gun shop owners give you a jaundiced look when you do this. You should see their eyes widen when the hammer drops. I once went to a favorite gun shop, he had just taken 10 model 10's and 15's in trade from the City PD for new 66's. The gent that owned this gun shop was friend, I sold guns for him if he got busy and ran his shop if he had to be out of town on Saturdays. I pulled a chair up to the counter where all of these Smiths were displayed. I was playing with a 10, it did not seem right, I pushed on the hammer, CLICK! I tried all the rest, CLICK! The owner called the Chief of PD immediatly, he chewed on him hard, He wanted money and them to come get the guns. They went into a we'll get back to you mode. I gave him a plan B. If they did not want to pay up, get them to buy all parts needed and I would rebuild them for him for one of the 15's. The City didn't want to pay but agreed to buying parts only. I rebuilt all 10. The chief had a patrolman who told all he was a GUNSMITH! They believed him, he worked over all the guns, my observation was he used a huge bastard file and a dry stone. There was not enough notch to; hell it was a speed bump. Good thing most cops shoot double action. The city boys found out and passed the liability by dumping them on the dealer. Shortly thereafter the city found out this guy was not a good cop and let him go. He's still out there some where, him and his big ole file.... This is why I check them all.
