Colt Mk. III Revolvers 
Trooper, Lawman, Official Police    USA

Colt Official Police mk. III

Colt Lawman mk. III

Colt Trooper mk. III

Click here to see Colt mk. III revolvers exploded parts view (25 Kb GIF)

Type: Double Action 
Chamber: .38 Special and .357 Magnum 
Weight unloaded: varies with different models and barrel lenghts 
Length: varies with different barrel lenghts 
Barrel length: 2.5, 4 or 6 inches (64, 102 or 152 mm) 
Capacity: 6 rounds 

The Colt mk. III family of revolvers appeared in the late 1960s as the first major development in the Colts' swing-out cylinder revolver design since early 1900s. The mk. III family consisted of the following major members: 
Official Police mk. III revolver - improved version of the famous Colt Official Police, rugged service firearm chambered for .38 Special only, with fixed sights. 
Lawman mk. III revolver - heavy barreled service revolver chambered for powerful .357 Magnum ammunition, with fixed sights 
Trooper mk. III revolver - service and target revolver, top-of-the line in the mk. III family. Chambered for .357 Magnum ammunition, with heavy, ribbed barrel and ejector rod shroud, removable front blade and ajustable rear sights. 

The key features of all mk.III revolvers are: 

  • the stainless steel firing pin is mounted inside the frame and is spring-loaded; it could be activated by the hammer only via the transfer bar, which is raised into the position only when trigger is pressed; othervise, hammer falls onto the frame and does not touch the firing pin 
  • cylinder rotates clockwise (when looking from behind the gun); this helps to hold proper chamber-to-barrel position, as cylinder rotation hand pressed it aganst the frame; 
  • all springs are made from stainless steel 
  • main stpring is of coil type, instead of the old, flat V-shaped spring 
  • all working surfaces are heat-treated to increase service life 
  • the cylinder rotation mechanism is redesigned, so cylinder can be opened or closed only if the hammer is lowered; if hammer is cocked, the cylinder rotation hand protrudes from iside the frame and blocks cylinder open or close operations.