a little bit from wiki about the Smith & Wesson Model 29 to kick-off.
The Smith & Wesson Model 29 is a six-shot, double-action revolver chambered for the powerful .44 Magnum cartridge, manufactured by the U.S. company Smith & Wesson. It was made famous by and is still most often associated with the fictional character "Dirty" Harry Callahan from the Dirty Harry
series of films starring Clint Eastwood.
The Model 29 was offered with 4", 5", 6", 6½", 8&3/8ths" and, later, 10&6/8ths" barrel lengths as standard models. Other barrel lengths were available either by special order from Smith & Wesson's Custom Shop or custom built by gunsmiths. The 5" barreled variant had a full length underlug. Finish options available included a highly polished blued or nickel-plated surface.
2 Model 29s with 4" & 8+3/8ths" barrels