Rimfire · Proprietary · Not SAAMI standardized · Not standardizedObsolete
.38 Long Rimfire
American rimfire cartridge used in early post-Civil War revolvers and single-shot pistols; predates the .38 Special by over two decades..
- Caliber
- 0.374″ · 9.5 mm
- Introduced
- 1868
- Case
- Rimmed
- Parent
- .38 Short Rimfire
- Primary use
- Target, Small game
- Status
- Discontinued
- Obsolete
- Obsolete
- Introduced
- 1868
- Type
- Rimfire
- Origin
- United States
- Inventor
- Various / American commercial
- Manufacturer
- Various / American commercial
- Standard
- Proprietary · Not SAAMI standardized · Not standardized
- SAAMI
- Not SAAMI standardized
- Obsolete
- Obsolete
- Status
- Discontinued
- Availability
- Rare
- Case capacity
- 16.8 gr H₂O
- Twist (typical)
- 1:20
- Primer
- Rimfire
- Case type
- Rimmed
- Max pressure
- 12,000 CUP, SAAMI crusher
- Eff. range
- 50 yd
- Max range
- 2350 yd
- Recoil
- 2.2 ft·lb
- Subsonic
- Capable
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for .38 Long Rimfire, so this is the shape gravity alone gives the advertised velocity. Drag would steepen it. The tool below solves real loads through their published G1 or G7 model.
Open in Ballistic Compare- Parent case
- .38 Short Rimfire
Representative trajectory — modeled from a single velocity input (no published BC for this cartridge yet).
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
Wikipedia · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 9.50 | 0.374 | · |
| Neck ⌀ | 9.55 | 0.376 | · |
| Shoulder ⌀ | n/a | ||
| Shoulder angle | n/a | ||
| Base ⌀ | 9.60 | 0.378 | · |
| Rim ⌀ | 11.00 | 0.433 | · |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.30 | 0.051 | · |
| Neck length | n/a | ||
| Case length | 22.20 | 0.874 | ~ |
| Overall length | 35.10 | 1.382 | ~ |
Size vs familiar rounds
Drawn at true 1:1 — every case is accurate relative to the others. Absolute size depends on your screen's pixel density, so measuring one against a real ruler may be off. .38 Long Rimfire is highlighted below.
Lineage
Connected reference
History
Introduced in 1868 as an improvement over the .38 Short Rimfire, the .38 Long Rimfire offered more powder capacity and was chambered in several Colt and Smith & Wesson revolvers of the Reconstruction era. Superseded by centerfire .38 cartridges in the 1880s.
FAQs
- What twist rate does .38 Long Rimfire use?
- .38 Long Rimfire typically uses a 1:20 twist rate.
- What bullet diameter is .38 Long Rimfire?
- .38 Long Rimfire uses a 0.374″ (9.5 mm) diameter bullet.
- Is .38 Long Rimfire still in production?
- .38 Long Rimfire is discontinued; typical availability is rare.
- What is .38 Long Rimfire used for?
- .38 Long Rimfire is primarily used for target, small game.
- What is .38 Long Rimfire based on?
- .38 Long Rimfire is derived from the .38 Short Rimfire case.
Sources & provenance
- Reference Gun Digest Books (Frank C. Barnes, ed. Richard A. Mann) — Cartridges of the World, 13th ed. — Barnes / Mann (.38 rimfire family) · velocity, bullet ⌀, grain weights
- Secondary Wikipedia (pointer to Barnes & Walter) — .38 rimfire (Long variant) · grain weights, velocity, year, bullet ⌀ archived
Data & sources. Specs compiled from the Lindcott Armory reference; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
