I know I've read and seen that the earlier M&P's slides were stamped Stainless on the left hand side but what I would liked to know (if any of you experts know) is when did S&W STOP stamping the slides on the M&P line? My M&P.40FS serial # DYB5xxx was assembled and test fired on Friday 27 Jul 2012 and it is not stamped stainless. Thanks All Later & Keep your Powder Dry! Dennis in Idaho "Those who Talk, Don't Do! Those who Do, Don't Talk!"