Browning Sweet Sixteen Serial Number Lookup
Collector Reference · Belgian FN Sweet Sixteen
Look Up Your Sweet Sixteen
Supports X-prefix 16-gauge serials (1947-1953), Sweet Sixteen S-prefix serials (1953-1957), and the listed year codes. X serials were shared with standard-weight 16-gauge Auto-5s.
Estimated Year
Era / Format
Collector Note
How to read this result: Results interpret published collector references; they are not factory letters or authentication. A manufacturing or shipping date requires individual verification. Consult Browning when a code is ambiguous or outside the listed ranges.
Not sure which Auto-5 you have? Review Belgian vs Japanese A5 identification, then confirm the gauge and Sweet Sixteen features before choosing a chart.
Browning Reading and Gun Care
- John Moses Browning: The Life and Legacy of the American Gunsmith Who Modernized Automatic and Semi-Automatic Firearms
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The Browning Sweet Sixteen is the lightweight 16-gauge variant of the Auto-5. This guide includes the shared 1947-1953 X-prefix sequence, the Sweet Sixteen S-prefix ranges, and later year codes. In 1953 Browning introduced separate model prefixes: S for the Sweet Sixteen and R for the standard-weight 16-gauge. An earlier X-prefix serial estimates a date but does not distinguish those two models.
How to Read Your Serial Number
An initial X followed by a number uses the 1947-1953 shared 16-gauge chart. The three S-code formats below apply to the later Sweet Sixteen sequence.
Era 1 · Late 1953–1957
"S" Prefix
S = Sweet Sixteen model code
31582 = Sequential production number
Era 2 · 1958–1968
Single-Digit Year + S
6 = Year digit (1966)
S = Sweet Sixteen
59455 = Sequential number
Era 3 · 1969–1975
Two-Digit Year + S
71 = Year (1971)
S = Sweet Sixteen
5103 = Sequential number
Early 16-Gauge Sequence (1909–1937)
This table covers the early general 16-gauge Auto-5 sequence, including years before the Sweet Sixteen. A numeric serial alone does not identify the lightweight model. The postwar X-prefix sequence (1947-1953) is listed separately below.
| Year | Serial Range | Notes |
|---|---|---|
| 1909 | 1 – 3,200 | 16-gauge sequence begins at FN |
| 1910–1913 | 3,201 – 15,000 | Last pre-WWI shipment: SN 19,642 |
| 1915–1918 | — | No production; German occupation of Belgium |
| 1919 | 19,671 – 20,500 | Production resumes post-WWI |
| 1920 | 20,501 – 22,237 | |
| 1921 | 22,238 – 24,050 | |
| 1922 | 24,051 – 26,000 | |
| 1923 | 26,001 – 28,400 | Barrel address: Browning Arms Co., Ogden, Utah |
| 1924 | 28,401 – 35,650 | |
| 1925 | 35,651 – 40,010 | |
| 1926 | 40,011 – 51,600 | |
| 1927 | 51,601 – 57,900 | |
| 1928 | 57,901 – 65,100 | |
| 1929 | 65,101 – 82,750 | Ventilated rib option added |
| 1930 | 82,751 – 90,500 | Address: Browning Arms Co., St. Louis, MO |
| 1931 | 90,501 – 94,000 | |
| 1932 | 94,001 – 96,072 | Three-shot "Auto 3" variant introduced |
| 1933 | 96,073 – 96,143 | |
| 1934 | 96,144 – 99,500 | Receiver legend updated with J.M. Browning bust |
| 1935 | 99,501 – 103,500 | |
| 1936 | 103,501 – 105,850 | Sweet Sixteen released — test market only |
| 1937 | 105,851 - 111,000 | Sweet Sixteen publicly available; no separate serial sequence yet |
X-Series 16-Gauge Auto-5 Serial Numbers (1947-1953)
Sweet Sixteens and standard-weight 16-gauge Auto-5s shared these X-prefix ranges. Keep the X when entering or reading a serial. Both endpoints of each range are included.
| Year | Serial range |
|---|---|
| 1947 | X1001-X13666 |
| 1948 | X13667-X23501 |
| 1949 | X23502-X34600 |
| 1950 | X34601-X43700 |
| 1951 | X43701-X59400 |
| 1952 | X59401-X77700 |
| 1953 | X77701-X99999 |
Source: NRA-hosted Blue Book serialization chart, PDF page 2, printed page 2359, Auto-5 16-gauge table. These are published reference ranges, not individual factory records.
Worked example: X92401 or X92404
Both X92401 and X92404 fall between X77701 and X99999, giving the same reference year: 1953. If a photograph leaves the final digit uncertain, retain that uncertainty in your records; the year estimate is unchanged for these two readings.
Does an X serial prove it is a Sweet Sixteen?
No. Model identification requires evidence from the gun itself. Compare the receiver's Sweet Sixteen marking, when present, and its lightweight construction. A matching X-series barrel serial helps assess whether the barrel and receiver numbers match; that match alone does not identify the lightweight model or establish originality. A serial photograph by itself is insufficient.
During 1953, Browning introduced S for Sweet Sixteen and R for standard-weight 16-gauge models. The chart dates both X-prefix and S-prefix examples to 1953, so the complete prefix matters.
S-Prefix Era (Late 1953–1957)
Use the Sweet Sixteen column of the cited NRA-hosted table. Its S49350 boundary overlaps two years; the lookup preserves that uncertainty and stops at the listed endpoint.
| Period | Approx. Serial Range | Notes |
|---|---|---|
| 1953 | S1–S3700 | Reference estimate |
| 1954 | S3701–S24850 | Reference estimate |
| 1955 | S24851–S49350 | S49350 also listed for 1956 |
| 1956 | S49350–S72300 | S49350 also listed for 1955 |
| 1957 | S72301–S99908 | Listed endpoint; do not extrapolate |
Year-Code Eras (1958–1976)
The year-code table repeats 8S for 1958 and 1968. Two-digit S codes begin with 69S. The cited reference ends these codes at 1975; unusual transition markings require individual verification.
| Year | Code Prefix | Example | Format |
|---|---|---|---|
| 1958 | 8S | 8S XXXXX | Single-digit code; also used in 1968 |
| 1959 | 9S | 9S XXXXX | Single-digit year |
| 1960 | 0S | 0S XXXXX | Single-digit year |
| 1961 | 1S | 1S XXXXX | Single-digit year |
| 1962 | 2S | 2S XXXXX | Single-digit year |
| 1963 | 3S | 3S XXXXX | Single-digit year |
| 1964 | 4S | 4S XXXXX | Single-digit year |
| 1965 | 5S | 5S XXXXX | Single-digit year |
| 1966 | 6S | 6S XXXXX | Single-digit year |
| 1967 | 7S | 7S XXXXX | Single-digit year |
| 1968 | 8S | 8S XXXXX | Repeated code; also used in 1958 |
| 1969 | 69S | 69S XXXXX | Two-digit year |
| 1970 | 70S | 70S XXXXX | Two-digit year |
| 1971 | 71S | 71S 5103 | Two-digit year |
| 1972 | 72S | 72S XXXXX | Two-digit year |
| 1973 | 73S | 73S XXXXX | Two-digit year |
| 1974 | 74S | 74S XXXXX | Two-digit year |
| 1975 | 75S | 75S XXXXX | Two-digit year |
| 1976 | No S code listed | Verify individually | 76S is not dated by this reference |
How to Identify a Sweet Sixteen — Physical Markers
The serial number tells you when; these physical features confirm what. A genuine Sweet Sixteen can be identified by several engineering differences from the standard-weight 16-gauge Auto-5.
Receiver Milling
Two mill cuts on each side at the bottom of the receiver near the loading port — a hallmark of the lightweight frame.
Barrel Ring
Three lightening holes drilled through the barrel ring (standard-weight guns have a solid ring).
Rib Width
Narrower ventilated rib than 12-gauge counterparts.
Stock
Interior of the stock is milled out to reduce weight by several ounces.
Weight
Typically 6 lbs. 8 oz. to 6 lbs. 12 oz. — noticeably lighter than a standard-weight 16-gauge.
Markings
Post-1937 guns are rollmarked "Sweet Sixteen" on the receiver; very early guns (1936–early 1937) may not carry this marking.
Safety
Early Sweet Sixteens have a front-trigger-guard safety; post-WWII guns have the rear safety tang.
"S" Receiver
Look for the S code stamped or embedded in the serial number on post-1953 guns.
Collector Notes — What to Know Before You Buy
- Late Belgian production and later Japanese production need model-specific confirmation. Check the country marking and complete serial format; do not infer a 1976 Sweet Sixteen date from the general Auto-5 production period.
- Do not apply the 12-gauge A5 serial number chart to a 16-gauge — the sequences started independently and will produce incorrect dates.
- A gun with an "R" prefix (not "S") is a Standard Weight 16-gauge, which is heavier and a different model. Use its separate reference column rather than applying Sweet Sixteen dates.
- Guns shipped from FN to Browning could sit in warehouse before reaching consumers. Browning can sometimes provide the ship date for a specific serial number.
Frequently Asked Questions
Starting in late 1953, Fabrique Nationale used the letter "S" as a model code for the Sweet Sixteen. Before 1953, Sweet Sixteens did not have a separate code and shared the general 16-gauge sequence. If your serial has a number-S prefix (like 6S or 71S), those digits indicate the year of manufacture.
The Sweet Sixteen is a lightweight variant — FN milled out the receiver sides, drilled the barrel ring, trimmed the rib, and hollowed the stock interior to reduce weight. A genuine Sweet Sixteen runs about 6¾ lbs., roughly 9–11 oz. lighter than the standard-weight 16-gauge.
That format (S-prefix only) dates your gun to late 1953 through 1957. In 1958, FN switched to embedding the year digit before the S. Use the S-Prefix chart above to narrow down the production period.
The general Auto-5 production transition is not an S-code year table. The cited Sweet Sixteen table has no 1976 S entry. Later Japanese guns use a different serial format; check the country marking and Browning’s later reference.
Value depends on condition, originality, era, and whether the original barrel is present. Belgian guns from the 1950s in excellent condition with matching barrels are generally the most desirable to collectors. Check recent auction results at Rock Island Auction or similar for current market values.
About Greg Cook
Greg Cook writes about firearms collecting, personal history, and the stories behind interesting guns. His Army MOS was 76Y, Unit Armorer, and he brings that practical background to his collector articles.
Sources and Further Reading
- Browning Auto-5 serial-number reference — manufacturer’s dating guidance and later model/date codes.
- NRA-hosted Blue Book serialization reference — Auto-5 serial tables, including model and gauge distinctions.
- NRA-hosted Blue Book X-series reference - 1947-1953 shared 16-gauge ranges and the 1953 model-prefix change; PDF page 2, printed page 2359.
- Gun Collectors Club Auto-5 serial-number guide — related collector reference.
X-prefix ranges and the 1937 numeric endpoint checked November 9, 2026. S-prefix and year-code boundaries reviewed September 28, 2026. Published early ranges can differ. Compare the complete serial format, gauge and model before relying on a date estimate; consult Browning for individual verification.