Doc, the stock firing pins were a headache for me. A pair of Open Tops would pierce the primers, develop high primers after firing, and on one of the sixguns the cylinder would jam because of high primers. The problem was worse with 125 gr cowboy loads, less so or not so with other manufacturers. Polishing chambers didn't help.
I sent the pair to Alan Harton in Houston who installed the Smith Shop firing pins after some polishing and shaping, and the problem went away. Alan also did a complete action job on the pair including rebuilding the hammer cam, hardening it, trigger job, polishing and hardening the hand, opening up the rear sight notch, installing new front sight with parallel sides and serrated backside.
The Open Tops are completely new pistols. They shoot everything without a problem including lightly loaded 38 Short Colts with 93 gr bullets, and all the ammo that had primer problems before the action job. Smooootttthhhhhh!
A second pair of Open Tops with serial numbers about 10 less than this first pair WOULD shoot all of my ammo but with occasional pierced primers, but no high primers. But they felt like they are filled with gravel when cocking. This pair is now with Alan for the same treatment including Smith Shop firing pins.
Stock firing pins were the cause of the primer problems, Smith Shop firing pins were a solution.