I just brought this home today. Yes, the frame is real brass. I took it off the gun and it is heavy brass with no reaction to a magnet. It is not brass plated aluminum or steel. It is marked XR3 and Alcoa in the "usual" area. The frame differs in some aspects to a regular aluminum XR3 frame that I have (note the upper area under the hammer). Was this ever a factory option ? I am aware of the "Dragoon style" Super Blackhawk size brass frames, but this is not that for sure ! It came on a .357 4 5/8" bbl Flat Top serial # 21397 (1959). The wear on the frame matches the wear on the overall gun. Any enlightenment you can provide will be appreciated.
Link to pics. on the S&W Forum http://smith-wessonforum.com/lounge/606491-help-1959-ruger-flat-top-357-brass-frame.html#post140617626
Link to pics. on the S&W Forum http://smith-wessonforum.com/lounge/606491-help-1959-ruger-flat-top-357-brass-frame.html#post140617626