The Colt .357 Mag. was in effect, a deluxe version of the Colt Trooper with a special Target Hammer, and over sized Target Grips.
It was made from 1953-1961 and came in 4" and 6" bbl's
Less than 15,000 were made.
The value for one in Excellent condition is about $700.00.
VG Condition is around $500.00
They were the Top of the line in the Colt Double Action stable until the Python came along in 1955 and demand for the .357 Magnum diminished.