Thanks for the advice, no, I haven't cleaned the rim cut and this was both factory and reloaded ammo. I talked to my gunsmith about this. He says he has seen this before. IF someone had done and improper 'trigger job' and had shortened the engagment on the hammer sear, then you can get a 'bounce' from the the trigger when the hammer passes it, causing the transfer bar to not engage as it should. When you check everything, looking and moving things, it won't show up, just during the firing stroke. The cure is a new hammer, I have one on order. I have not done anything to this, bought it a few years ago and had this problem when I got it. But the firing pin was bent, and dragging on the frame. I trued it up and have had no problems since. Now it has suddenly started doing this. 44 Man