I'm told that Bill Davis made more than than a few of these.The colt barrel has a 4 1/4" twist nd the S&W barrel is 4 1/8 twist so they joined the best of both pistols. I'm told bulls eye shooters in the late 70's early 80's had them custom made. AS FOR WHY?iIt's a sweet shooting nice looking, different handgun that not everyone else has. Soooo. WHY NOT!