Belgian Browning Auto-5 Serial Code Decoder
Use this Browning serial number lookup reference to narrow the likely manufacture period and identify the correct Auto-5 model or series. Enter or compare the available markings, then verify the result against the supporting serial-range notes and collector references below.
By Greg Cook · Updated September 28, 2026 · Collector Reference
Decode Your Serial Number
Enter the serial number exactly as it appears on your receiver. Include any prefix letters and digits — no spaces.
Need the full A5 tool and charts? Open the Browning A5 serial number lookup.
Browning Reading and Gun Care
- John Moses Browning: The Life and Legacy of the American Gunsmith Who Modernized Automatic and Semi-Automatic Firearms
- TempPro TP50 hygrometer Same unit as the ThermoPro TP50 on the humidity guide. Cheap, and it tells you if the safe is wet.
- Birchwood Casey Synthetic Gun Oil 10-Ounce Aerosol Long-Lasting Gun Lubricant The natural solvency of Synthetic Gun Oil cleans as it oils while its low evaporation rate assures protection against rust.
How to Look Up a Browning Auto-5 Serial Number
This decoder covers Browning Auto-5 shotguns made by FN in Belgium and explains the later Japanese Miroku system for comparison. It does not date every Browning rifle, pistol, or shotgun model. Getting an Auto-5 date right requires identifying the serial-number era and the model letter—if present—before choosing a production table.
- Copy the complete receiver serial: include every letter, digit, and prefix in the order stamped.
- Confirm the maker: check for “Made in Belgium,” Liège proofs, or “Made in Japan” before selecting the FN or Miroku system.
- Decode the model letter: use the table below to separate Standard Weight, Light Twelve, Magnum, Sweet Sixteen, Standard 16, and Twenty variants.
- Compare the correct era: match the full format—not merely the numeric portion—then verify gauge, weight, barrel, and proof markings.
Belgian Auto-5 production ran from 1902 through 1976 and passed through several serial formats as production expanded, WWII interrupted output, and FN introduced model codes. Published ranges can estimate manufacture periods, but factory documentation remains the better source when an exact date is important.
Model Letter Code Quick Reference
If your serial number contains a letter, find it here first.
| Letter | Model | Gauge | Weight | Production Years | Notes |
|---|---|---|---|---|---|
| H | Standard Weight (early) | 12 ga. | Standard | 1954–1956 | Used briefly; replaced by M in 1957 |
| M | Standard Weight | 12 ga. | Standard | Early M series; year codes through 1969 | Primary 12-ga. standard code |
| G | Light Twelve | 12 ga. | Light | 1956–1976 | Preceded by L; early sources differ |
| L | Light Twelve (early) | 12 ga. | Light | 1953–1956 (reference range) | Compare the Light Twelve source notes |
| V | Magnum | 12 ga. | Standard | 1958–1976 | 3-inch chamber; V = Magnum |
| S | Sweet Sixteen | 16 ga. | Light | S-prefix and year codes: 1953–1975 | Preceded by separate 16-ga. sequence |
| R | Standard Weight 16 | 16 ga. | Standard | R-prefix and year codes: 1953–1963 | Reference stops before 1964; verify later markings |
| Z / X | Light 20 / Magnum 20 | 20 ga. | Light / Magnum | 1958–1976 | Z: Light 20; X: Magnum 20 from 1967 |
| (none) | Standard Weight 12 | 12 ga. | Standard | 1902–1953 | Pre-letter era; all digits |
| ABC | Remington wartime | All | — | 1940–1946 | A = 16ga, B = 12ga, C = 20ga; US-made |
The Six Belgian Serial Number Eras
FN's serial number system evolved over 74 years of production. Understanding which era your gun belongs to is the first step to dating it accurately.
Pre-War Sequential (1902–1939)
All-digit serial numbers · 12-gauge only · No letter codes
From the model's introduction through the outbreak of WWII, FN used a single sequential number series for all 12-gauge Auto-5s. No model letter, no year code — just a number. Pre-war guns begin at serial number 1 and run to approximately 228,000. Precise year-by-year breakdowns are not available from FN's records; the table below reflects Browning Arms Company data.
| Year | Serial Range | Notes |
|---|---|---|
| 1902–1903 | 1 – ~5,000 | First U.S. shipment; marked "BROWNING AUTOMATIC ARMS CO. OGDEN UTAH" |
| 1904–1910 | ~5,001 – ~45,000 | — |
| 1911–1914 | ~45,001 – ~100,000 | — |
| 1915–1918 | No Belgian production — German occupation of Belgium; FN factory seized | |
| 1919–1930 | ~100,001 – ~160,000 | Production resumes; address changes to Browning Arms Co., St. Louis, MO |
| 1931–1939 | ~160,001 – 228,000 | Three-shot "Auto-3" variant available; J.M. Browning bust added to receiver legend |
WWII Remington Production (1940–1946)
A/B/C prefix · US-made · Not Belgian FN
With Belgium under German occupation beginning in 1940, Browning licensed Auto-5 production to Remington Arms in the United States. Remington-made guns are identified by the letter prefix: A for 16-gauge, B for 12-gauge, and C for 20-gauge. These are American guns — mechanically similar to the Belgian original but not FN-manufactured.
| Code | Gauge | Notes |
|---|---|---|
| A | 16 gauge | US-made by Remington; marked on receiver |
| B | 12 gauge | US-made by Remington |
| C | 20 gauge | US-made by Remington |
Post-War Belgian Sequential (1946–1953)
All-digit continuation · 12-gauge standard weight · No letters
FN resumed Belgian production in 1946, picking up the sequential series where it had left off. Serial numbers in this era are all-digit, running from 229,000 to approximately 438,000 by the end of 1953. No model letter is present; all guns in this range are 12-gauge standard weight unless the receiver is marked otherwise.
| Year | Serial Range |
|---|---|
| 1946 | 229,001 – 237,000 |
| 1947 | 237,001 – 249,000 |
| 1948 | 249,001 – 270,000 |
| 1949 | 270,001 – 285,000 |
| 1950 | 285,001 – 315,000 |
| 1951 | 315,001 – 346,000 |
| 1952 | 346,001 – 387,000 |
| 1953 | 387,001 – 438,000 |
Letter Code Introduction (1953–1958)
H / L / M / G / S / R prefixes introduced
Early letter-prefix ranges differ between published sources. For L and G numbers, compare the Light Twelve source notes; do not treat a model-letter summary as an exact year.
| Year | Code Change |
|---|---|
| 1953–1956 | Early L range in the collector table; Browning groups L1–L83000 under 1954–55 |
| 1953 | S prefix introduced for Sweet Sixteen; R prefix for Standard Weight 16ga |
| 1954 | H prefix introduced for Standard Weight 12ga (replaces all-digit for new production) |
| 1956 | G replaces L for Light Twelve; H continues briefly |
| 1957 | M replaces H for Standard Weight 12ga; G, S, and R continue |
| Prefix | Model | Years | Approx. Range |
|---|---|---|---|
| L | Light Twelve | 1953–1956 | L 1 – L 99,877 |
| H | Standard Weight 12ga | 1954–1956 | H 1 – H 99,000 |
| G | Light Twelve | 1956–1958 | G 1 – G 99,663 |
| M | Standard Weight 12ga | 1957 | M 22,000 – M 85,000 |
| S | Sweet Sixteen | 1953–1957 | S 1 – S 99,908 |
| R | Standard Weight 16ga | 1953–1957 | R 1 – R ~40,000 |
Single-Digit Year Code (1958–1968)
Format: [digit][letter][serial] · 20-gauge introduced
Single-digit year codes require the model letter. The code 8 repeats in 1958 and 1968 for M, G, S and V; it is not a unique year. The 20-gauge codes differ: Z identifies Light 20, while X identifies Magnum 20 from 1967.
| Year | Digit | Model Codes Active |
|---|---|---|
| 1958 | 8 | 8M (SW12), 8G (LT12), 8S (Sweet16), 8R (SW16), 8V (Mag12), 8Z (20ga) |
| 1959 | 9 | 9M, 9G, 9S, 9R, 9V, 9Z |
| 1960 | 0 | 0M, 0G, 0S, 0R, 0V, 0Z |
| 1961 | 1 | 1M, 1G, 1S, 1R, 1V, 1Z |
| 1962 | 2 | 2M, 2G, 2S, 2R, 2V, 2Z |
| 1963 | 3 | 3M, 3G, 3S, 3R, 3V, 3Z |
| 1964 | 4 | 4M, 4G, 4S, 4V, 4Z |
| 1965 | 5 | 5M, 5G, 5S, 5V, 5Z |
| 1966 | 6 | 6M, 6G, 6S, 6V, 6Z |
| 1967 | 7 | 7M, 7G, 7S, 7V, 7X |
Two-Digit Year Codes: Model-Specific Transition
Year digits + model code + serial sequence; transition varies by model
For the 12- and 16-gauge tables, two-digit year codes start in 1969. The 20-gauge table uses 68Z and 68X. Do not apply one transition year to every model; unusual markings need individual confirmation.
| Year | Prefix | Active Models |
|---|---|---|
| 1968 | 8 / 68 | 8M, 8G, 8S, 8V; 68Z, 68X for 20-gauge |
| 1969 | 69 | 69M, 69G, 69S, 69V, 69X |
| 1970 | 70 | 70G, 70S, 70V, 70X |
| 1971 | 71 | 71G, 71S, 71V, 71X |
| 1972 | 72 | 72G, 72S, 72V, 72X |
| 1973 | 73 | 73G, 73S, 73V, 73X |
| 1974 | 74 | 74G, 74S, 74V, 74X |
| 1975 | 75 | 75G, 75S, 75V, 75X |
| 1976 | 76 | 76G, 76V, 76X — Final year of Belgian FN production |
Post-1976: Japanese Miroku Serial Numbers
Beginning in 1976, production shifted to Miroku in Japan. The Japanese serial system is completely different from the Belgian FN system and must not be cross-referenced with the charts above.
Miroku Serial Number Format
[Serial Number] + [Date Letter] + [Date Letter] + [Type Code]
Example: 01001RT151
- 01001 = Serial number
- R = Date letter (R = 7)
- T = Date letter (T = 6) → 76 → 1976
- 151 = Magnum 12-gauge
Date Letter Decode
Type Code Reference
| Type Code | Model |
|---|---|
| 151 | Magnum 12 gauge |
| 161 | Magnum 20 gauge |
| 211 | Light 12 gauge |
| 221 | Sweet Sixteen |
| 231 | Light 20 gauge |
How to confirm Miroku production: Look for "Made in Japan" on the barrel. Belgian guns are marked "Made in Belgium" or carry Belgian proof marks (star-in-oval, ELG crown).
Belgian Proof Marks — Confirming FN Origin
Belgian FN guns carry government proof house marks from Liège. These appear on the barrel, receiver, and sometimes the magazine tube. Knowing these marks confirms a gun is genuinely Belgian — important when a serial number alone leaves doubt.
ELG in Oval (Crowned)
Definitive Belgian Liège proof. Appears on virtually all FN production. The crown over ELG signifies nitro proof acceptance.
Star in Oval (PV)
Smokeless powder provisional proof. Common on all post-1898 Belgian guns.
Perron Symbol
Liège city symbol (a pillar with spheres). Appears on guns proved at the Liège proof house.
Inspector's Initials
Small letter stamps, often found on barrel flats. Indicate individual inspector acceptance — helpful for dating within a production window.
Common Dating Mistakes to Avoid
- ✕ Do NOT apply the 12-gauge chart to a 16-gauge gun. The Sweet Sixteen (S prefix) and Standard Weight 16 (R prefix) ran completely independent serial sequences.
- ✕ The H prefix (1954–56) is easily confused with a date digit. If your serial looks like H12345, the H is a model code, not a year indicator.
- ✕ Guns shipped from FN could sit in Browning's warehouse for months or even years before sale. The serial number gives the manufacture year, not the purchase year.
- ✕ A gun with no letter prefix and a number below 228,000 is almost certainly pre-WWII. A number between 229,000 and 438,000 is post-war Belgian (1946–1953).
- ✕ Japanese Miroku guns are well-made and should not be dismissed — but they are not Belgian. The two systems are completely separate.
Frequently Asked Questions
Enter the complete Auto-5 receiver serial exactly as marked, including every letter and year digit. Use the model-letter table to identify gauge and weight, then compare the number with the matching Belgian FN era or later Miroku code system.
Not in every case. Some Belgian Auto-5 eras use approximate ranges, records are incomplete, and shipment or sale dates can differ from manufacture dates. Treat the decoder as an estimate and use factory records when an exact documented date matters.
Check the barrel's “Made in Belgium” or “Made in Japan” marking, Liège proof marks, gauge and chamber marking, receiver model letter, weight configuration, and other barrel and receiver codes.
Check the barrel marking — Belgian guns say "Made in Belgium" and carry Liège proof marks (ELG in crowned oval, star in oval). Japanese guns say "Made in Japan." Additionally, Belgian production ran 1902–1976; any Auto-5 built after 1976 is Japanese Miroku. The serial number format also differs completely.
A pure all-digit serial places your gun in one of three windows: 1–228,000 is pre-WWII Belgian (1902–1939); 229,001–438,000 is post-war Belgian (1946–1953). All-digit guns are 12-gauge standard weight — FN's letter system was introduced specifically to mark new variants.
M identifies a standard-weight 12-gauge Auto-5. Early references differ; the cited year-code table stops at 69M. Verify later or unusual M markings individually.
S identifies Sweet Sixteen; R identifies standard-weight 16-gauge. Their separate reference columns have different endpoints. Use the model-specific chart, and do not extrapolate one model’s dates to another.
Yes — with the WWII exception. From 1902 through 1939, and again from 1946 through 1976, all Belgian-market Auto-5s were manufactured by Fabrique Nationale de Herstal in Liège, Belgium. The 1940–1946 guns with A/B/C prefix codes were made by Remington Arms in the United States under wartime license.
V = 12-gauge Magnum, chambered for 3-inch shells. The Magnum variant was introduced in 1958 alongside the year-code system, so all V-prefix guns have a year digit or two-digit year before the V. Example: 4V = 1964 Magnum; 72V = 1972 Magnum.
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.
- Gun Collectors Club Auto-5 serial-number guide — related collector reference.
L/G and S boundaries and model-specific year codes 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.