If, God forbid, you should have to shoot someone with any firearm that has had a trigger job, the guy's family attorney will rip you a new one in court for carrying around a handgun with a "hair trigger." We all know it's Bravo Sierra, but all he has to do is convince a bunch of people who aren't bright enough to get out of jury duty.
1. It used to be quite common for police to have trigger jobs done on their service revolvers. It's not quite as common today with automatics, but it does occur.
2. A "hair trigger" doesn't exist on a DOA revolver, period. Once you get under about 7-8 pounds of pull weight on a leaf spring gun, you'll be limited to using federal ammo and/or federal primers if you want the gun to go bang when the trigger is pulled. On a coil spring J frame, 9-10 pounds is the realistic limit with any degree of reliability. You can go lighter, but again, it'll be federal ammo and/or federal primers only. Do you really think anyone can claim that the weight of a gallon of milk(or more) is a "hair trigger"?
If we were discussing a 1.5 pound trigger on a 1911, you might have a point.
3. I hope, quite sincerely, that folks such as yourself are never involved in a deadly force situation. I suspect you'll be too busy worrying about inapplicable bull**** to shoot when required. If it's a good shoot, it's a good shoot. If not, too bad.
For the original question--- Pull weights are going to vary some from gun to gun depending on how well the parts are fitted and if it's a new or used gun. New guns are probably in the 14 pound range. One that's been shot some might drop a pound or so, as well as being a little smoother.
Mom recently bought a new 642, and while I didn't measure the pull before working on it, I did measure it after. After some polishing and changing the rebound spring, it's at 11.5 pounds(and a very noticeable improvement). I suspect that after it gets a little more use, it will drop slightly.