Was on the John Ross site (He wrote, "Unintended Consequences") and saw his link for downloading this nice write up:
http://www.john-ross.net/pdfs/maghist.pdf
"The Development of the Powerful Big-Bore Revolver in General and the .500 S&W Magnum in Particular And The Development of the John Ross/Performance Center 5" .500 S&W Magnum With Suggestions and Recommendations For Owners of These Guns
By
John Ross "
http://www.john-ross.net/pdfs/maghist.pdf
"The Development of the Powerful Big-Bore Revolver in General and the .500 S&W Magnum in Particular And The Development of the John Ross/Performance Center 5" .500 S&W Magnum With Suggestions and Recommendations For Owners of These Guns
By
John Ross "