I have a 625 and a 610. I have had problems with light strikes when firing d/a but not s/a. In both situations, the culprit has been the tensioning screw on the main spring ( think I am stating the name of the parts correctly ). Overtime, the screw had loosened. After taking the grips off, I tightened the screw and the problem went away. I was told by a gunsmith that when firing in single action, there was more force.
You would think that a new revolver would not have that problem.I use what ever type of primers are available. Lately Win l. p. which are $30. otd from lgs.
I am not an expert on revolvers but your situation sounds like problems I have had.