There was a story floated in Hollywood and elsewhere that a S&W Model 57 in .41 Magnum was used as a *stand-in* weapon in some of the scenes where it could be seen only from the side [and not the muzzle] due to a shortage of available Model 29's in the blue finish at the time of filming. Amusingly, the original script called for a nickel-plated gun, and with the four-inch barrel, not the 6 1/2-inch target gun eventually used by Eastwood, who is tall enough to get away with it.
However, both Clint Eastwood and scriptwriter John Milius have denied this, and S&W most certainly did provide several handguns used in the first movie.
Oh, and *Dirty Harry* was a loosely-based composite of not one, not two, but THREE San Francisco PD *Inspectors* [SFPD designation for detectives] of which only one carried- and used- a magnum revolver in the performance of his duty, back when he was still a uniformed SFPD patrol Sergeant. But it was a .357 Colt Python, not a Smith & Wesson. And he was the one who got the credit for the arrest of Sara Jane Moore following her fumbled attempt on the life of President Gerald Ford, and that was only one high point of his career that got him his Inspector's badge.
