I have been fooling around with Wolff spring kits in S&W revolvers lately. So far I have done 3, 2 L frames, 1 N frame. The L's worked fine, but the N frame experienced quite a few misfires. The N is my falling plates competion gun, so I went back to the stock mainspring, and the problem disappeared. The L frames were older guns, the N is new production, (ugly lock in the side, and maybe worst, CAST! hammer and trigger, UGHH!) Anyways, could the lighter looking hollowed out hammer be part of the light firing pin strikes?