Just curious, everyone here has been talking about getting the light hits or misfires and then going around and still getting a misfire, thinking possibility of off center hits or light spring(Wolff). What primers are we talking about? Rotating the shell around 90 degrees and getting it to fire tell me the priming component not consistent in primer possibly, or primer not seated and bottomed out good, or inconsistent in bottom of pocket. Crushing a primer when seating.Some hand seat the primers because they get the feel better for consistent seat.
Dont forget to check end shake in yoke and cylinder. Sooner or later it will open up after lot of shooting. Short hammer fall(falls just at time it locks up) can cause misfires if action has been worked on. Most of time strain screw backed out too far for that lighter pull. Just some "other" thoughts. Still cant get Federal small pistol primers here.