I recently bought one that mis-fires occasionally.
We compared it to another, that I just gifted my son, and it appears, visually, that the hammer nose, firing pin or whatever it's called - is just a tad shorter.
I'm not a gunsmith, so is there anything I should be checking before looking for a revolver-smith?

I suppose it’s possible that the firing pin was replaced, Or full hammer. Check protrusion by opening cylinder and pushing hammer forward while trigger is pulled. Compare that to your other pistol. Also check your mainspring under the grips as people often fool with that. Make sure screw is tight and nothing has been inserted between spring and frame.
That’s about all you can do without help from a smith.

75% of the time a used S&W has misfire issues it's bc someone backed out the strain screw to get the DA pull weight down.

First check that the strain screw (which presses against the mainspring) is tight. Often people just loosen them and leave them. Even a 1/2 turn can make the difference between the gun firing and not.

If the strain screw is tight, but DA pull weight feels nice and smooth (ie low weight), either buy another strain screw, and buy a stock mainspring, and replace them. Strain screws are like $3 each, a mainspring might be $10

Edit: this is not a gunsmith job...it's an opportunity to get friendlier with your revolver. All it takes is a screwdriver.

Agreed. Replacing a hammer is pretty straight forward to but as I tell my better half when a plumbing project comes up, "I'm just an out of work cowboy gunfighter..."

Agreed. Replacing a hammer is pretty straight forward to but as I tell my better half when a plumbing project comes up, "I'm just an out of work cowboy gunfighter..." Then I say, "but if the demand for those ever comes back honey, you are Set!!"

Mr. Shubert, if by chance you find that the spring itself has been diddled somehow, shoot me a PM and I'll send you one. Got plenty of spares on hand.