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The manufacturer’s own lookup returns two different years for one number

The maker’s own lookup returns two years

When the primary source contradicts itself, the reader has nowhere to go. The corpus contains the exact thread: a Colt owner entering one serial number into Colt’s own website and getting the same model back twice, with two different years.

A real case

From the record

The thread is titled, by its own author, "Stupid Question: Colt Serial Number Lookup has 2 Dates for a Serial Number" — the model listed once against 1975 and once against 1976, with the question: "Does this mean that the gun was made in 1975 but shipped in 1976 or that there are duplicates?"

What actually produces the discrepancy

A serial can legitimately appear against more than one entry when the source lists overlapping spans, when a range is repeated for a model that was catalogued across a boundary, or when the lookup matches on a family rather than resolving to one row. The result is not two facts — it is one uncertainty rendered as two rows.

What to watch for

A lookup that returns a year for any number is not resolving anything. The corpus records the criticism directly: "The Colt Serial Number Lookup does nothing more than give a year and model for the number you enter. Enter a bogus number, get a bogus answer." A tool that cannot fail cannot inform. This site’s own lookup deliberately returns an explicit failure reason rather than a nearest match.

What to do about it

Working with this cause
  • Read a two-row answer as an unresolved range, not as two dates. The truth is between them, and the table cannot narrow it further.
  • Test the tool: enter a number that cannot exist and see whether it still returns a confident year. If it does, you have learned how much its answers are worth.
  • Where the maker’s own lookup disagrees with itself, the archive is the tie-breaker — see the records pages for who holds this maker’s factory ledgers.
  • Record both years and the tool that produced them. "1975 or 1976, from the manufacturer’s lookup" is an honest entry; picking one is a guess.

Sources for this page: 1911Forum — "Colt Serial Number Lookup has 2 Dates for a Serial Number".

Other reasons two sources disagree

The table and the gun disagreeThe published table is known to be impreciseThe numbers are not in the order you assumeThere is nothing left to checkThe number on the gun is not the original one
The lookup shows its working

Every result names the chart it came from, the threshold it rests on, and — where the published table is documented as imprecise — says so on the result itself rather than returning a bare year.

Open the serial number lookup All the causes

Compiled and sources last checked 2026-10-14. This page explains a documented discrepancy; it does not date your firearm.