Birdshot
Many smaller pellets form a pattern. In the U.S. size examples below, a higher birdshot number means a smaller pellet. Lead, steel, bismuth, and tungsten-based products of the same numbered size need not have the same mass or behavior.
THE CARTRIDGE LIBRARY · SHOTSHELL
28 gauge
A smaller conventional shotgun gauge with established target and upland loads and newer specialty sporting offerings. Gauge describes bore size rather than pellet diameter.
2A Ledger reference desk · Sources checked October 18, 2026
Read the dimensions
- Folded length · max
- 2.500 in
63.500 mm - Nominal shell class
- 2¾ in
69.850 mm - Bore diameter · min
- 0.545 in
13.843 mm - Rim diameter · max
- 0.687 in
17.450 mm
Know the exact name
At a glance
- Cartridge family
- Shotshell
- Bore specification
- 0.5450 in / 13.843 mmBore minimum
- Factory examples
- 4 shot loadsSelected catalog examples
- Weight in cited examples
- Ounces / pellet countPayload is separate from gauge
28 gauge is identified by its complete cartridge designation. The resource-table alternative is 28 ga. A caliber number, bullet diameter, or family resemblance on its own does not identify ammunition compatibility.
A sparse buckshot listing in one catalog is not proof that no such product exists. The exact factory examples below show what the cited source actually lists.
Dimensions: open the exact dimensional drawing ↗. The displayed number is bore minimum, rather than an assertion that every manufactured projectile or barrel has this exact diameter.
Origins & evolution
Background & development
The 28 gauge established its sporting identity around small, light shotguns and modest shot charges. Winchester added a 28-gauge Model 12 in 1934, extending that pump-action family into a much smaller bore. The relatively uncommon version later became a notable collector’s variant, while the gauge itself retained an audience among upland hunters and clay-target shooters.
American skeet gave the 28 gauge a formal competitive home alongside the 12, 20 and .410 bore. Its more recent history includes development beyond the familiar 2¾-inch target shell: in June 2023, SAAMI announced acceptance of an Olin Winchester 3-inch 28-gauge specification, covering both lead and non-lead shot loadings. That milestone shows a continuing effort to broaden the gauge’s ammunition options. It does not turn older 28-gauge guns into 3-inch-chambered firearms; the new specification is a distinct chapter in an established small-bore sporting tradition.
Historical sources: American Rifleman: 1934 28-gauge Model 12 introduction ↗ · SAAMI: June 2023 acceptance of the 3-inch 28-gauge shotshell ↗ · NSSA: World Skeet 28-gauge competition ↗
Construction changes the story
Loads, variations & specialty offerings
Gauge identifies the bore family. Shot number identifies the approximate diameter of an individual pellet. Ounces describe the combined shot payload, while a buckshot product may specify a pellet count. Shell length is a separate chamber-fit specification, normally referenced to the fired shell.
Buckshot
Fewer, larger pellets are commonly listed by size and pellet count. #4 birdshot and #4 buckshot have very different diameters. Pattern behavior depends on the exact load, firearm, and choke; there is no universal inches-per-yard rule.
Slugs
A slug is a single projectile. Rifled/Foster-type and sabot designs have different barrel recommendations. Federal identifies sabot loads for rifled barrels; follow the exact ammunition and barrel maker’s instructions.
Materials & specialty loads
Lead & bismuth
Lead remains common in target and upland loads where permitted. Bismuth is an alternative material offered in selected sporting loads; compare the maker’s product specification and shotgun/choke compatibility.
Steel
Steel shot has different density and hardness from lead. A shot-size label alone does not reproduce the same pellet mass. Use ammunition approved for the barrel and choke; check current local hunting requirements separately.
Tungsten-based & specialty
TSS and other tungsten-based products can use small pellets and dense payloads. The exact alloy and construction matter. Mixed-shot, reduced-recoil, short-shell, and handgun-marketed products retain their own firearm restrictions.
Compare pellet sizes visually
The two circles use the same screen scale to compare nominal pellet diameter. They are not life-size, do not represent a shot pattern, and do not show an individual load’s pellet count.
See nominal pellet sizes in inches and millimeters
| Pellet | Inches | Millimeters |
|---|---|---|
| #9 birdshot | 0.08 | 2.032 |
| #8 birdshot | 0.09 | 2.286 |
| #7½ birdshot | 0.095 | 2.413 |
| #6 birdshot | 0.11 | 2.794 |
| #5 birdshot | 0.12 | 3.048 |
| #4 birdshot | 0.13 | 3.302 |
| #3 birdshot | 0.14 | 3.556 |
| #2 birdshot | 0.15 | 3.810 |
| #1 birdshot | 0.16 | 4.064 |
| BB birdshot | 0.18 | 4.572 |
| BBB birdshot | 0.19 | 4.826 |
| T birdshot | 0.2 | 5.080 |
| #4 buckshot | 0.24 | 6.096 |
| #3 buckshot | 0.25 | 6.350 |
| #2 buckshot | 0.27 | 6.858 |
| #1 buckshot | 0.3 | 7.620 |
| 00 buckshot | 0.33 | 8.382 |
| 000 buckshot | 0.36 | 9.144 |
Federal: shotshell components and nominal shot sizes ↗
Factory shot-load examples
| Product code | Load family | Shell length (in) | Payload | Shot size | Muzzle velocity |
|---|---|---|---|---|---|
| PWBX285 | Steel birdshot | 3 | ¾ oz | 3, 4 | 1,400 fps 427 m/s |
| P283 | Lead field birdshot | 2¾ | ¾ oz | 6, 7½, 8 | 1,295 fps 395 m/s |
| PTSSX289F | Tungsten-based specialty birdshot | 2¾ | 1¼ oz | 9 | 1,100 fps 335 m/s |
| PTSSX285F | Tungsten-based specialty birdshot | 3 | 1½ oz | 9 | 1,050 fps 320 m/s |
No 28-gauge buckshot appears in the selected Federal table. This guide does not invent a buckshot specification or infer that other makers cannot offer one.
Explore the published data
Ballistics you can inspect
Shotshell muzzle velocity, pellet patterns, and slug trajectories answer different questions. Birdshot and buckshot cannot be represented as a single bullet curve: individual pellet drag and pattern behavior require a load-specific test. The pellet comparison above shows size, not performance.
What can be plotted reliably?
The sources checked for this guide do not provide a comparable barrel-length series. A single factory muzzle-velocity specification does not establish a velocity curve. The factory records and any missing test conditions are identified below.
An estimate needs an anchor and a defensible method. No curve has been invented from bullet diameter or from another cartridge’s name.
Direct answers
Common questions
What is 28 gauge?
A smaller conventional shotgun gauge with established target and upland loads and newer specialty sporting offerings. Gauge describes bore size rather than pellet diameter.
Is 28 gauge a shot size?
Gauge or bore identifies the shell and bore family. Birdshot and buckshot size labels describe individual pellets. The load also needs a payload, shell length, material, and exact product identification.
Are similarly named cartridges interchangeable?
A sparse buckshot listing in one catalog is not proof that no such product exists. The exact factory examples below show what the cited source actually lists.
Are the graph values measured or estimated?
This guide has no supported multi-point graph in the sources reviewed. Its factory specifications and source links are shown in the load section.
Does higher energy mean the best load?
Energy is calculated from mass and velocity. It does not establish accuracy, expansion, penetration, pattern density, recoil, or suitability for a particular firearm. Use the exact product documentation and firearm manual.
Trace the facts
Sources & methodology
Compiled by 2A Ledger from the linked standards, manufacturer publications, and identified test records. Checked October 18, 2026. Historical tests and older catalogs retain their original dates; a listing here does not establish current availability.
- SAAMI: dimensional drawing · PDF p. 38 ↗
- Federal: shotshell components and nominal shot sizes ↗
- Federal: 2026 ammunition catalog ↗
- American Rifleman: 1934 28-gauge Model 12 introduction ↗
- SAAMI: June 2023 acceptance of the 3-inch 28-gauge shotshell ↗
- NSSA: World Skeet 28-gauge competition ↗
Diameter figures preserve the cited drawing convention. Inch–millimeter conversion uses exactly 25.4 mm per inch. Factory specifications describe the maker’s test setup; your firearm, ammunition lot, temperature, and measuring method can produce different results. This is an educational factory-ammunition reference, not a reloading manual.