What we know as simply the “Magnum” is really the Colt Python double-action revolver. The real article is chambered in .357 just like its video game counterpart, and is lauded for its accuracy and smooth, satisfying operation.
Introduced in 1955, the Python is far too new to be associated with images of the Wild West, and in fact features several design elements that make it better than the pistols toted by old gunslingers. Such features include: “precision adjustable sights, a smooth trigger, solid construction, and extra metal,” according to Wikipedia. Perhaps more distinctively, it sports a solid underlug for stability and a ventilated rib on the top side of the barrel.
One major feature that separates it from its forebears is the tight cylinder action, in which the cylinder stays locked in place for the duration of the hammer strike. Along with a design that utilizes a tight gap between the cylinder and the forcing cone, these modern elements greatly aid both accuracy and velocity for the round being fired.
The Magnum’s real-life counterpart is able to be fitted with a number of different barrels and other attachments to suit different roles. The version we see in-game is representative of the most popular model utilizing a 6-inch (15cm) barrel, but the Python is also available with 2.5-inch (6.4cm), 3-inch (7.6cm), 4-inch (10cm), and 8-inch (20cm) barrels. For a time, Colt offered a “Python Hunter” model which featured a 2X Leupold scope fixed with Redfield mounts, meant to be used as a hunting weapon.
Picture by CalGuns.net user “beetle.”
Image of Colt Python Hunter model with scope can be seen here: http://www.rockislandauction.com/photos/57/p_standard/OPD252-G-F1-H.jpg