Dating a colt trooper mkiii is postdating a check
PRODUCTION REVOLVERS The Trooper was offered in a variety of formats upon customer request.
Calibers offered were the .38 Special, the .357 Magnum starting in 1961, and in .22LR.
Colt offered the Trooper with a choice of any combination of Target hammer, Target grips, Service hammer or Service grips.
TROOPER WITH SERVICE GRIPS AND HAMMER The Colt's of the early 1950's were fitted with the first type of Colt Accro rear sight.
The only real change was to thicken the top strap to allow extra metal so an adjustable rear sight could be installed.
The new revolver was introduced in 1953 and was an immediate success with law enforcement and civilian shooters.
By the later 1950's, Colt changed the design of the Accro sight slightly.
With sales of the 357 down, Colt decided to simplify the line in 1961 by discontinuing the 357 and offering the Trooper in .357 Magnum as well as .38 Special.
The Trooper .38 and .357 serial numbers were shared with the .38 Officer’s Model Match and the 357 model.