Colt Serial Number Lookup & Year-by-Year Identification Guide

How to Read Colt Serial Numbers

Start with the entire serial number exactly as stamped. Colt used plain numeric sequences, letter prefixes, letter suffixes, hyphenated suffixes, and later multiple letter blocks. A number such as 1001, MT1001, 1001-S, 1001-C, and 001001S can point to entirely different Woodsman-era guns.

Understanding Prefixes and Suffixes

Prefixes appear before the number, suffixes appear after it. On some Colt models the letter position is the key. A Government Model serial with C before the number generally belongs to an earlier commercial run than one with C after the number. Python serial numbers used no letter through most of the 1955-1969 period, then shifted through E-prefix, E-suffix, V, K, T, and other later letter blocks.

Where to Look

• Revolvers: check the frame, crane/yoke area, butt, and barrel markings.
• 1911 / Government Model pistols: check the frame serial number first; slide markings help identify variant but are not the legal serial location.
• Pocket pistols and Woodsman models: check the frame and slide area, then compare the serial format to the correct model family.

Colt Serial Number Lookup by Model

Colt Serial Number Lookup Tables: Quick Reference

Quick-Reference Colt Serial Number Summary

Colt Python Serial Number Lookup

The Python was introduced in 1955 as Colt's premium double-action revolver. Early production (1955–1969) used a plain numeric serial number with no letter prefix or suffix. Beginning late in 1969, Colt transitioned to letter-prefix serials (E-prefix) and later used multiple letter combinations to comply with the Gun Control Act of 1968 unique-number requirement.

Table 1A — Colt Python No-Letter Era (1955–1969)

Table 1B — Colt Python Letter-Prefix / Letter-Suffix Era (1969–1985+)

Collector Notes — Python

• Pre-64 premium: Revolvers below serial 30,800 carry the strongest collector premium because of finish quality, hand-fitted actions, and the hollow underlug design associated with early production.
• Hollow vs. solid underlug: The hollow underlug is an early feature; verify by looking at the barrel lug profile from the muzzle end.
• Finish: Royal Blue finish is the most desirable. Nickel and stainless examples were offered in later years and carry their own collector interest.
• Barrel lengths: 2.5", 4", 6", and 8" were offered at various times. 2.5" examples are the scarcest.
• Modern reissue: Colt reintroduced the Python in 2020 with new serial numbers; these are entirely distinct from all vintage production.

Colt 1911 / Government Model Serial Numbers

The Government Model was adopted by the U.S. Army in 1911 and has been in continuous or near-continuous production since 1912. Commercial production used a "C" prefix from 1912 through approximately 1949, then transitioned to a "C" suffix from late 1949 through 1970. The MKIV/Series 70 was introduced in 1970 with a new serial system. The M1911A1 military contract ran through 1945 alongside commercial production. No commercial production occurred 1943–1945.

Table 2A — Colt Government Model Commercial C-Prefix Era (1912–1949)

Table 2B — Colt Government Model C-Suffix Era (1949–1970)

Table 2C — M1911A1 U.S. Military Production, Key Ranges (1924–1945)

Collector Notes — Government Model / 1911

• Prefix vs. suffix: "C" moved from prefix to suffix in late 1949; both are genuine commercial Colts from different ends of the same production period.
• Series 70 (1970): The MKIV/Series 70 introduced a collet-type bushing and dropped the C-series number convention entirely.
• Series 80 (1983): Firing pin safety added; recognized by the transfer bar in the slide.
• National Match / Gold Cup: These target variants share the commercial serial range but carry "NM" or "GC" markings and should be researched separately.
• WWII contractors: Singer, North American Arms, and Remington-UMC pistols are the rarest military variants.

Colt 1903 Pocket Hammerless Serial Numbers

The Colt 1903 Pocket Hammerless (formally the Model M) was designed by John Browning and produced from 1903 through 1945, with nominal post-war assembly of small quantities through 1947. Total production reached approximately 570,000 units. A companion model, the 1908 in .380 ACP, followed the same basic design with a separate serial range. The 1903 is catalogued in five types based on physical changes over the production run.

Table 3A — Colt 1903 Pocket Hammerless Type Identification

Table 3B — Colt 1903 Pocket Hammerless Year-by-Year Serial Numbers

Collector Notes — 1903 Pocket Hammerless

• OSS and General Officer pistols: WWII-era examples with documented military assignment carry significant provenance premium. Colt Archive Letters are especially important for these.
• Grip change: Checkered hard rubber grips with rampant colt were standard through 1923; checkered walnut with medallion replaced them from 1924 onward.
• 1908 .380 ACP companion: The Model 1908 (.380 ACP / 9mm Short) used its own serial range beginning at 1 in 1908 and running to approximately 138,000 by end of production (1940). These are catalogued separately from the 1903 .32 ACP.
• Beware misidentification: The unrelated 1903 Pocket Hammer (.38 ACP) shares the model year name but is a completely different pistol. Verify caliber and hammerless profile.

Colt Detective Special and Cobra Serial Numbers

The Detective Special was introduced in 1927 as a compact, six-shot derivative of the Police Positive Special, chambered initially in .32 New Police, .38 New Police, and .38 Special. The Cobra appeared in 1950 as an alloy-frame variant of the same D-frame design, offering comparable capacity at significantly reduced weight. Both models shared serial number blocks with other D-frame revolvers (Agent, Commando) through much of their production life, which can complicate precise dating without a factory letter. Collectors divide the Detective Special into four major issues: First Issue (1927–1946) — square butt (1927–1932/33), then round butt; pre-war fit and finish. Second Issue (1947–1972) — post-war frame and sight revisions; ramp front sight; updated stocks. Third Issue (1973–1986) — fully shrouded ejector rod; long ramp front sight; .38 Special dominant. Fourth Issue (1993–1995/1996) — revival production; limited run.

Table 4A — Detective Special Serial Numbers, Shared D-Frame Range

Table 4B — Colt Cobra Key Production Notes

Notable provenance: Jack Ruby's Cobra, serial number 2744LW (the "LW" denoting Light Weight aluminum frame), sold at auction for $220,000.

Collector Notes — Detective Special and Cobra

• Round vs. square butt: The square-butt First Issue is harder to find in original condition; round-butt transition occurred 1932/1933.
• Shrouded ejector rod: The Third Issue (1973+) is the most common and least expensive; Second Issue examples in excellent condition are more sought after.
• Cobra vs. Detective Special: Both are D-frame revolvers. The sole functional difference is the Cobra's aluminum alloy frame vs. the Detective Special's steel frame.
• Dating challenge: Because D-frame models shared serial number blocks, the model name must be confirmed by physical inspection or factory letter.

Colt Woodsman and Match Target Serial Numbers

The Woodsman line was introduced in 1915, based on a John Browning design, and remained in production for more than sixty years through three distinct series. The Match Target variation — most commonly called the "Bullseye" Match Target — appeared in 1938 with a heavy barrel profile suited to target work. Serial number conventions changed significantly between series, and numbers from different series can appear similar; using the full prefix/suffix is essential to correct dating. Related budget models (Challenger, Huntsman, Targetsman) shared some serial blocks and are noted where relevant.

Table 5A — First Series Woodsman (1915–1947)

Table 5B — First Series Match Target “Bullseye” (1938–1944)

Table 5C — Second Series Woodsman (1947–1955)

Table 5D — Challenger (1950–1955)

Table 5E — Third Series Woodsman (1955–1977)

Table 5F — Huntsman and Targetsman (1955–1969)

Collector Notes — Woodsman and Match Target

• Serial number format is critical: Serials 1001, MT1001, 1001-S, 1001-C, and 001001S are all valid Woodsman numbers from different eras — 1916, 1938, 1948, 1950, and 1969 respectively. Always read the complete serial including all letters.
• Non-sequential assembly: The Woodsman was not assembled in strict numerical order. Overlaps of several thousand numbers are common; a lower serial does not always mean an earlier ship date.
• Match Target premiums: Pre-war First Series Match Target "Bullseye" examples (MT prefix) are the most desirable. Heavy barrel profile and original stocks add collector value.
• Magazine variations: Pre-war and post-war magazines are not interchangeable between all series; original matching magazines enhance collector value significantly.
• Bullseye nickname: The Match Target name is official; "Bullseye" is a widespread collector nickname referencing the heavy-barrel target-shooting tradition the pistol was built for.

Related Colt Guides

• Colt Python Identification Guide
• Colt Python Serial Prefix Eras
• Colt Woodsman Match Target Guide
• Colt 1911 and Government Model Guide
• Colt Cobra and Detective Special Guide
• Firearm Serial Number Guides