Winchester Model 1866 (Model 66) serial numbers by year
The “Yellow Boy” — Winchester’s first rifle, a brass-framed lever action developed from the Henry. Its serial numbers continue the Henry sequence, which is why the table begins at 12,476 rather than 1.
- Produced:
- 1866–1898
- Action:
- lever-action
What year was your Model 66 made?
Winchester Model 66 value: what it sells for at auction
140 Winchester Model 1866s sold one gun to a lot at Rock Island Auction Company (114) and Morphy Auctions (26) between Sep 2023 and Sep 2026. The table groups them the way the auction house coded each lot: antique, curio and relic, or modern. Half of the guns in each row sold inside the “most sell between” range; a quarter sold below it and a quarter above. Eight in ten sold inside the wider “nearly all between” range.
Standard guns only. Left out: deluxe and special-order guns (checkered or fancy wood, pistol grips, odd barrel lengths, special sights), engraved, inscribed, presentation, and commemorative pieces, and lots of two or more guns. A deluxe or special-order gun sells for more than these figures, often several times more. Condition and originality drive most of the spread inside a row.
Enter your serial number above and this section picks out the row for your gun’s era and lists the most recent sales like it.
| Era | Sales | Most sell between | Typical | Nearly all between |
|---|---|---|---|---|
| Antiquemade before 1899 | 139 | $4,406 – $9,400 | $6,000 | $3,672 – $15,275 |
By configuration
The same sales split by what the lot title called the gun, all eras together.
| Configuration | Sales | Most sell between | Typical | Nearly all between |
|---|---|---|---|---|
| Carbine | 66 | $4,595 – $9,400 | $6,231 | $3,754 – $14,688 |
| Rifle | 55 | $4,847 – $9,988 | $6,462 | $3,840 – $15,275 |
| Musket | 19 | $3,600 – $4,990 | $4,112 | $3,396 – $8,225 |
These are sold prices for standard guns, not an appraisal. Prices realized as published by each house after the sale; both houses' figures include the buyer's premium. A dealer buying for resale will offer less than these figures; a private sale between collectors often lands near the typical price for the gun’s condition. If your gun has factory upgrades, a factory letter that confirms them is what moves it above these numbers. Updated after each major sale. The full picture, model by model →
Where the serial number is
Varies by model: internal on the side of the lower tang on First and early Second Models; externally behind the trigger on later Second and Third Models; farther rearward between the lever latch and tang screw on Fourth Models.
Where these dates come from
Winchester's original factory records do not cover every model. For the Model 1866, the dates come from one published source, George Madis's published tables. It was typed up long after production, so treat any year as a close estimate rather than a factory record.
Sources for this model: Madis model variation ranges · Winchester customer-service list (2012)
Winchester Model 1866 serial numbers by year
The full Model 1866 serial number chart, one table for each published source. Each row gives the serial numbers that source assigns to a year. Find the row your number falls in.
The tables agree with each other for every serial range. A row marked “approximate” comes from a table whose figures are estimates rather than factory records.
George Madis's published tables
From George Madis's Winchester books, a collector reference compiled decades after production. The figures are year-end estimates, not counts from the factory books.
Cited as: Madis model variation ranges
| Year | Serial numbers |
|---|---|
| 1866–1867 | 12,476 – 15,578 |
| 1867–1869 | 15,579 – 25,000 |
| 1869–1878 | 25,001 – 149,000 |
| 1878–1898approximate | 149,001 – 170,100 |
- 1866–1867: This is the approximate serial range and the approximate years for the First Model.
- 1867–1869: This is the approximate serial range and the approximate years for the Second Model.
- 1869–1878: This is the approximate serial range and the approximate years for the Third Model.
- 1878–1898: This is the approximate serial range and the approximate years for the Fourth Model. The final serial is disputed. George Madis's tables end the sequence at about 170,100, while the factory records at the Cody Firearms Museum reach 170,101, one number higher.
Winchester's own customer-service list (2012)
A year-by-year list Winchester's customer-service desk typed up to answer owners' letters. Partly real records and partly estimates, as the list itself says.
Cited as: Winchester customer-service list (2012)
| Year | Serial numbers |
|---|---|
| 1866 | 12,476 – 14,813 |
| 1867 | 14,814 – 15,578 |
| 1868 | 15,579 – 19,768 |
| 1869 | 19,769 – 29,516 |
| 1870 | 29,517 – 52,527 |
| 1871 | 52,528 – 88,184 |
| 1872 | 88,185 – 109,784 |
| 1873 | 109,785 – 118,401 |
| 1874 | 118,402 – 125,038 |
| 1875 | 125,039 – 125,965 |
| 1876 | 125,966 – 131,907 |
| 1877 | 131,908 – 148,207 |
| 1878 | 148,208 – 150,493 |
| 1879 | 150,494 – 152,201 |
| 1880 | 152,202 – 154,379 |
| 1881 | 154,380 – 156,107 |
| 1882 | 156,108 – 159,513 |
| 1883 | 159,514 – 162,376 |
| 1884 | 162,377 – 163,649 |
| 1885 | 163,650 – 163,664 |
| 1886 | 163,665 – 165,071 |
| 1887 | 165,072 – 165,912 |
| 1888 | 165,913 – 167,155 |
| 1889 | 167,156 – 167,401 |
| 1890 | 167,402 – 167,702 |
| 1891 | 167,703 – 169,003 |
| 1893 | 169,004 – 169,007 |
| 1894 | 169,008 – 169,011 |
| 1897 | 169,012 – 169,015 |
| 1898 | 169,016 – 170,100 |
What to know about Model 1866 serial numbers
- There is no single year-by-year serial number table for the Model 1866 that everyone accepts. Sources vary slightly.
- George Madis's tables give quantities for each variation that add up to about 192,600. That total does not match the serial ranges or either reported final serial. Do not treat those quantities as settled counts for each variation.
- Henry rifle numbers overlap Model 1866 numbers during the changeover, so a final serial is not a clean count of Model 1866 production.
- Numbers 174,100 and above were reportedly given to the repair department, not to ordinary production.
- Letters at or near an early Winchester serial number are not part of the number when you search the factory records at the Cody Firearms Museum.
- Every original Model 1866 counts as an antique under the pre-1899 antique cutoff. The last reported production was in 1898.
- Winchester's own customer-service list is a retyped compilation, not the original records. The list itself says that no complete original serial record from 1866 onward is known to exist, and that some of its figures are estimates.
Other Winchester lever-action rifles
Winchester rifles that never had a serial number
These have no serial number to look up. Their pages explain why, and how to date one from its features.
Want proof on paper? Order a factory letter
The Cody Firearms Museum holds Winchester’s original records and, for a fee, will search them for your serial number and send you a letter with the recorded dates and details. It is the closest thing to the original factory entry you can own, and it is what auction houses and appraisers accept.
Its records cover Model 1866 serial numbers: 124,995–170,101, plus a few scattered early numbers. A number outside that coverage cannot be lettered.
Order a factory letter from the Cody Firearms Museum →What a factory letter shows, and when one is worth ordering →