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
10 gauge
A large conventional shotgun gauge. Factory ammunition commonly emphasizes substantial sporting payloads, but shot size, material, and shell length remain separate specifications.
2A Ledger reference desk · Sources checked October 18, 2026
Read the dimensions
- Folded length · max
- 3.110 in
78.994 mm - Nominal shell class
- 3½ in
88.900 mm - Bore diameter · min
- 0.775 in
19.685 mm - Rim diameter · max
- 0.933 in
23.698 mm
Know the exact name
At a glance
- Cartridge family
- Shotshell
- Bore specification
- 0.7750 in / 19.685 mmBore minimum
- Factory examples
- 2 shot loadsSelected catalog examples
- Weight in cited examples
- Ounces / pellet countPayload is separate from gauge
10 gauge is identified by its complete cartridge designation. The resource-table alternative is 10 ga. A caliber number, bullet diameter, or family resemblance on its own does not identify ammunition compatibility.
10 gauge is a bore family, not a pellet-size number. A 3½-inch catalog shell requires an appropriately marked chamber.
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 10 gauge belongs to the older large-bore sporting-shotgun tradition, with a particularly strong association with waterfowling. Its later commercial history centered on heavy-payload guns rather than the lighter, general-purpose shotguns that made the 12 gauge dominant. Ithaca’s Mag-10 autoloader, catalogued during the 1970s, gave the gauge a distinctive modern self-loading platform.
The transition toward non-lead waterfowl ammunition renewed interest in the space available for larger shot and substantial payloads. Federal’s early Premium offerings included a 3½-inch 10-gauge load, while Browning added a 10-gauge BPS in 1988. Browning’s subsequent Gold 10 and Remington’s SP-10 continued the purpose-built autoloader tradition. These developments explain the gauge’s specialized following: its modern story is tied to substantial waterfowl guns and ammunition systems, rather than to being a larger version of every ordinary 12-gauge field load.
Historical sources: American Hunter: Ithaca’s 1970s Mag-10 development context ↗ · American Hunter: Federal archive history and early 10-gauge Premium load ↗ · Browning: 1988 10-gauge BPS introduction ↗ · American Hunter: original evaluation of later 10-gauge platforms ↗
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 |
|---|---|---|---|---|---|
| PWBX107 | Steel birdshot | 3½ | 1⅝ oz | BB, 2 | 1,375 fps 419 m/s |
| P108F00 | Lead buckshot | 3½ | 18 pellets | 00 | 1,100 fps 335 m/s |
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.
Select a legend entry to add or remove its line. Hover or tap a plotted point, or use the position slider. With the graph focused, arrow keys move the inspector. Solid dots identify source points; dashed connectors show estimates between them. Load construction, pressure category, and test setup can differ even at the same grain weight.
Read the original values as accessible tables
10 gauge: factory velocity downrange
| Exact load | Source | Published points |
|---|---|---|
| 766 gr Federal 3½-inch rifled hollow-point slug | Federal | 0: 1280; 25: 1170; 50: 1090; 75: 1020; 100: 970; 125: 930 |
Source records for plotted slugs
| Maker / product | Bullet mass | Published construction | Muzzle velocity | Test barrel | Source |
|---|---|---|---|---|---|
| FederalF103F RS | 766 gr 49.64 g | 3½-inch rifled hollow-point slug | 1,280 fps 390 m/s | 32 in | Federal · PDF p. 63 ↗ |
Direct answers
Common questions
What is 10 gauge?
A large conventional shotgun gauge. Factory ammunition commonly emphasizes substantial sporting payloads, but shot size, material, and shell length remain separate specifications.
Is 10 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?
10 gauge is a bore family, not a pellet-size number. A 3½-inch catalog shell requires an appropriately marked chamber.
Are the graph values measured or estimated?
The downrange view uses the exact manufacturer catalog records shown in the source table. Dashed connectors and intermediate inspector values use linear interpolation between the displayed source points. Calculated energy uses the listed bullet mass and velocity.
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. 27 ↗
- Federal: shotshell components and nominal shot sizes ↗
- Federal: 2026 ammunition catalog ↗
- Federal · PDF p. 63 ↗
- American Hunter: Ithaca’s 1970s Mag-10 development context ↗
- American Hunter: Federal archive history and early 10-gauge Premium load ↗
- Browning: 1988 10-gauge BPS introduction ↗
- American Hunter: original evaluation of later 10-gauge platforms ↗
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.