I believe that if you research the spur, or "hook" on the trigger guard, looking for any design patent or clue on the origin, you will come up empty handed, sooner or later. Very few American made handguns, except S&Ws, are seen with it, if any. It is seen on middle Eastern manufactured handguns, circa 19th century, which leads to the conclusion that it facilitated "holstering" the gun in a sash or waistband. Trying to place your fingers around the "hook" when firing the revolver is a clumsy exercise, which seems to eliminate it as an improvement in shooting the revolver, however S&Ws efforts to offer the option of a hook to shooters during the period of target shooting as a popular activity leads one to believe S&W thought it was helpful, somehow. Not too many American target shooters wore sashes to their matches, so that theory didn't apply here. Ed.