Practice & target
Full-metal-jacket, plated, lead, and wadcutter bullets describe different constructions. Grain weight is projectile mass; it does not state a powder charge or guarantee recoil.
THE CARTRIDGE LIBRARY · PISTOL
.38 Super
A semiautomatic-pistol cartridge commonly labeled .38 Super Auto +P. Its small semi-rim and history of competition use distinguish it from .38 Special.
2A Ledger reference desk · Sources checked October 18, 2026
Read the dimensions
- Overall · min–max
- 1.220–1.280 in
30.988–32.512 mm - Case length · max
- 0.900 in
22.860 mm - Bullet maximum
- 0.356 in
9.042 mm - Rim diameter · max
- 0.406 in
10.312 mm
Know the exact name
At a glance
- Cartridge family
- Pistol
- Bullet specification
- 0.3560 in / 9.042 mmBullet maximum
- Factory examples
- 1 loadsSelected, sourced examples below
- Weight in cited examples
- 115 grGrains measure mass, not powder charge
.38 Super is identified by its complete cartridge designation. The resource-table alternative is 38 Super Automatic +P. A caliber number, bullet diameter, or family resemblance on its own does not identify ammunition compatibility.
.38 Super ammunition must not be used in older pistols intended only for .38 ACP. Similar external dimensions do not mean equal operating specifications.
Dimensions: open the exact dimensional drawing ↗. The displayed number is bullet maximum, rather than an assertion that every manufactured projectile or barrel has this exact diameter.
Origins & evolution
Background & development
Colt introduced the .38 Super in 1929, building on John Browning’s older .38 ACP cartridge of 1900. It paired a substantially more powerful loading with the M1911-type pistol. The commercial idea was to obtain greater performance from an established automatic-pistol cartridge family, rather than to create a smaller pocket-pistol round.
The Super’s reputation changed again with practical-pistol competition. Earlier barrels commonly located the semi-rimmed cartridge by its small rim, and inconsistent headspacing contributed to disappointing accuracy. In the early 1980s, competition interest encouraged improved barrels that located the cartridge at the case mouth. Sierra credits that development with revealing accuracy that the older arrangements had obscured. The resulting revival made the .38 Super closely associated with USPSA/IPSC competition. Its story therefore has two distinct turning points: Colt’s 1929 introduction and the competition-driven technical refinement decades later.
Historical sources: Sierra: .38 Super cartridge history ↗
Construction changes the story
Loads, variations & specialty offerings
Expanding factory bullets
JHP, XTP, FTX, HST, and similar product names refer to particular designs. Muzzle energy alone does not show expansion, penetration, or reliability in a particular firearm.
Specialty load families
Reduced-recoil, subsonic, monolithic, and heavier-bullet offerings are product-specific. A +P marking is a pressure category where standardized, not simply a heavier bullet. Follow the maker’s exact product and firearm guidance.
In the cited .38 Super examples, bullet weights are 115 grains. These are the weights actually present in this source selection, not a claim that every possible loading is listed.
Bullet construction background: Hornady: anatomy of a bullet ↗. Exact product descriptions and velocities are cited in the factory table.
From the factory catalog
115 grains
1,130 fps
JHP · +P
Compare all 1 cited factory load records
| Maker / product | Bullet mass | Published construction | Muzzle velocity | Test barrel | Source |
|---|---|---|---|---|---|
| FederalAE38S3 | 115 gr 7.45 g | JHP +P | 1,130 fps 344 m/s | 5 in | Federal · PDF p. 61 ↗ |
Explore the published data
Ballistics you can inspect
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
.38 Super: factory velocity downrange
| Exact load | Source | Published points |
|---|---|---|
| 115 gr Federal JHP +P | Federal | 0: 1130; 25: 1067; 50: 1016; 75: 974; 100: 938 |
How to interpret the comparison
Changing bullet weight also often changes bullet design and propellant choice. Two curves are comparisons of the listed products, not a controlled experiment proving that bullet weight alone caused the difference. Catalog downrange points are projections under the maker’s conditions; barrel-study points are recorded observations in the study firearm.
Direct answers
Common questions
What is .38 Super?
A semiautomatic-pistol cartridge commonly labeled .38 Super Auto +P. Its small semi-rim and history of competition use distinguish it from .38 Special.
What diameter does .38 Super use?
The cited dimensional standard lists 0.3560 inches (9.042 mm), bullet maximum. This drawing convention is different from a casual caliber nickname.
Are similarly named cartridges interchangeable?
.38 Super ammunition must not be used in older pistols intended only for .38 ACP. Similar external dimensions do not mean equal operating specifications.
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
Skives & petals: read the jacket construction →
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. 50 ↗
- Sierra: .38 Super cartridge background ↗
- Federal · PDF p. 61 ↗
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.