Manufactured in 1939 and is one of only 625 standard frame first generation SAAs chambered in .357 Magnum (see David Brown's "The 36 Calibers of the Colt Single Action Army," page 182. Although introduced in 1935 towards the end of first generation production, the .357 Magnum cartridge was popular, including with highway and law enforcement agencies looking for a powerful cartridge that could with proper loads stop a car by damaging its engine. The .357 Magnum was the last cartridge Colt introduced to the first generation line of SAAs. This standout example features a barrel with the one-line Hartford address on top and "COLT SINGLE ACTION ARMY .357" on the left side. The left side of the frame carries the two-line patent dates marking followed by a Rampant Colt. The left side of the trigger guard is marked with the number "4" above a Colt factory triangle proof. The matching assembly number "762" appears on the loading gate and rear of the frame. Matching serial numbers appear on the frame and right side of the trigger guard, back strap under the grip panel, and back of both grip panels. The last two digits of the serial number ("84") are stamped on the rear face of the cylinder. The original Colt factory box is numbered to the gun.