Hutch’s black Colt Python .357 magnum revolver (left) is probably the gun that most people remember from Starsky & Hutch. Introduced in 1955, the Python soon became a popular gun in law enforcement until automatic 9 mm pistols (such as Starsky’s Smith & Wesson, also in the screenshot above) overtook revolvers in general in that area. Colt discontinued the production of Pythons completely in 2005.
Apparently, the Python’s 6-inch model was more popular with uniformed officers, while the plain-clothes detectives preferred the 4-inch model. Incidentally, Hutch carries both in the show, but the 6-inch model is probably seen more often (according to Barb’s site, he only uses the 4-inch model in the first few episodes of Season 1 – I haven’t checked). Here he’s reloading the 4-inch Python (with a brown handle) in 01-01 Savage Sunday. (In the pilot, he carried a snub-nosed Smith & Wesson Model 10.)
Both of Hutch’s Magnums came with royal blue finish, but here’s a good photo of a Python with nickel finish, complete with the package and the manual, from 1978 (I think, the print on the manual is borderline readable). Specifications of the gun can be found e.g. on Wikipedia.
Yes, it’s big… and it’s loaded. Surely you’re not supposed to point it at your partner, with your finger on the trigger?