just bought my first center fire handgun after 30 years. i could not be more impressed. i believe this gun was sent to the factory for aftermarket work. the trigger feels like my target rifles. of all the guns i looked at the s&w impressed me the most and now i would like to know even more. how can i date it and learn the guns history. what is the best powder for 158 gr. lswc? thank you for your support.