Went to the range today for some live fire, sight check before this weekend's match. Loaded mags, sent the target downrange, double action pull feels much smoother after some polishing and grease, and...
Soft thud, FTF. Racked slide and caught the round - no primer strike. Tried again, same result.
Black O-ring was well camouflaged in the black hammer groove. Removed the O-ring, fires much better now. D'Oh!