Especially on Ruger Mark pistols. Over the years I have found that to be the case and can vouch for the through hardness of Ruger Mark sears. During the hardening process, in many cases the pivot pin hole will become distorted, and sorta elliptical. I have a set of carbide reamers in 0.001 increments that I'll use to get that pivot pin hole back to being round again so they work more smoothly. That does go beyond what some owners really need, but it does make for a much smoother operating trigger pull.