Well, I’m not sure on a revolver, maybe spring pockets, but my gunsmith just last week had to use a hand reamer on my BRAND NEW S&W M&P 2.0 stuck drop safety plunger hole.
Those are broaches. Primarily used for enlarging small pin holes, and for clearing obstructions (damage) from pin cavities. Several of these in different sizes were provided in the armorer's tool kit sold by S&W.