Colt Trooper Mk III
- Category
- Revolver
- Barrel
- 152 mm
- Weight, empty
- 1.13 kg
- Introduced
- 1969
About
What it is, and why it matters
The Colt Trooper Mk III is an American double-action/single-action service revolver introduced in 1969 as the top of Colt's Mk III line. It features a heavy ribbed barrel with a full ejector-rod shroud, adjustable target sights, a target trigger and hammer, and a transfer-bar safety. Internally it introduced Colt's new investment-cast, coil-mainspring 'Mk III' action that replaced the older hand-fitted leaf-spring Colt lockwork, allowing a durable revolver to be built more cheaply to compete with Smith & Wesson. It was also offered in .22 LR, .22 WMR and .38 Special.
The Mk III introduced Colt's investment-cast, coil-mainspring action that replaced the company's older hand-fitted leaf-spring lockwork, a deliberate cost-cutting redesign to compete head-to-head with Smith & Wesson while the hand-fitted Python stayed the flagship; it was also the first Colt revolver with a transfer-bar safety, allowing it to be carried with all six chambers loaded.
Common barrel lengths 4", 6" and 8". Part of the Mk III family alongside the Lawman Mk III and Official Police Mk III. Superseded by the Trooper Mk V (1982-1985).
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Colt's Manufacturing Company LLC
- Category
- Revolver
- Country
- United States
- Status
- Discontinued
- Produced
- 1969 to 1983
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 152 mm
- Weight, empty
- 1.13 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Recoil operated
- Firing mechanism
- Double action single action
- Trigger
- Double action
- Trigger pull
- 69.0 N
- Capacity
- 6
- Magazine
- Rotary
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Steel
- Barrel
- Steel
- Stock
- Wood
- Finish
- Blued
BallisticsFrom the service cartridge, not a handload.
- Muzzle energy
- 704 J
- Effective range
- 50 m
Trajectory
What the round does downrange
Solved from the muzzle figures and the bullet. The dashed rule is the effective range on the record, and the crosses are the steps the solver returned.
Features
What it has
What the record lists as fitted, drawn from the catalogue.
Heavy ribbed barrel
Full ejector rod shroud
Ramped front sight
Adjustable rear sight
Target hammer
Target trigger
Coil spring action
Swing out cylinder
Standing
How it compares
Each figure against the firearms of the same type and cartridge that record it, or of the same type where that cartridge has too few. Positions are read to the nearest tenth.
| Measurement | This firearm | Median | Position |
|---|---|---|---|
| Empty weightAmong 53 .357 Magnum revolvers | 1.13 kg | 1.10 kg | Heavier than about 60% |
| Barrel lengthAmong 53 .357 Magnum revolvers | 152 mm | 107 mm | Longer than about 90% |
| Magazine capacityAmong 53 .357 Magnum revolvers | 6 | 6 | Near the median |
Answers
Questions about the Colt Trooper Mk III
How much does the Colt Trooper Mk III weigh?
The Colt Trooper Mk III weighs 1.13 kg (2.50 lb) empty.
What caliber is the Colt Trooper Mk III?
The Colt Trooper Mk III is chambered in .357 Magnum.
How many rounds does the Colt Trooper Mk III hold?
The Colt Trooper Mk III holds 6 rounds, fed from a rotary magazine.
How long is the Colt Trooper Mk III?
The Colt Trooper Mk III has a 152 mm (5.98 in) barrel.
Who makes the Colt Trooper Mk III?
The Colt Trooper Mk III is made by Colt's Manufacturing Company LLC (United States).
When was the Colt Trooper Mk III introduced?
The Colt Trooper Mk III was introduced in 1969 and discontinued in 1983.
How does the Colt Trooper Mk III operate?
The Colt Trooper Mk III uses a recoil operated action, and its firing mechanism is double action single action.
Compatibility
Which parts fit this firearm
Studio
Every part that mounts on this, resolved
Not a list the maker typed out: the answer comes from the mounts this firearm exposes and the interface each part needs, so it stays right when either one changes.
- Every part that mounts on any firearm in the catalogue
- Interface standards, platforms and fit overrides
- The same answers through the API and the MCP server
Requires a signed-in GunSpec account on the Studio plan. The answer is computed per part, so it is not part of the public record.
Provenance
What the record holds
Every figure above was taken from one of these pages. The confidence reflects how much of the record came from a page a claim can be checked against.
In service
- United States police agencies
- United States
Provenance
Confidence in this record
66%
Stockists
Where to buy
Offers link straight to the shop. GunSpec never takes the order.
No shop has listed this firearm yet
Stock and prices come from the shops themselves. If you sell this firearm, you can list it and it appears here.
List a firearmMCP
Ask an assistant about it
The same record, reached the way a person asks for it rather than the way a program does.
Ask GunSpec
Works with
Point an MCP client at GunSpec and it answers from the catalogue rather than from memory. A free key covers the read tools.
API
The call that returns this record
The same fields, in the same units, from the same endpoint the page reads.
curl --request GET \ --url 'https://api.gunspec.io/v1/firearms/colt-trooper' \ --header 'X-API-Key: your_key'{ "id": "colt-trooper", "name": "Colt Trooper Mk III", "manufacturer": { "id": "colt", "name": "Colt's Manufacturing Company LLC", "countryCode": "US", "foundedYear": 1855, "website": "https://www.colt.com", "logoUrl": null, "description": "American firearms manufacturer headquartered in Hartford, Connecticut. Founded in 1855 and now a subsidiary of Colt CZ Group, continuing production of iconic firearms including the 1911 pistol.", "status": "active", "defunctYear": null, "stateOwned": null, "makesFirearms": null, "parentId": null, "predecessorId": null, "createdAt": "2026-02-11 23:44:38", "updatedAt": "2026-02-18 03:43:38", "version": "7143c7ff3f7e156063a240f2df7b4746ee1c0394d7cd5f592d05bac43233d637" }, "category": { "id": "revolver", "name": "Revolver", "description": "Handguns with a revolving cylinder containing multiple chambers" }, "country_of_origin": "US", "year_introduced": 1969, "barrel_length_mm": 152, "weight_empty_g": 1134, "action_type": "recoil_operated"}