What twist rate does .38-40 Winchester use?

.38-40 Winchester typically uses a 1:36 twist rate.

What bullet diameter is .38-40 Winchester?

.38-40 Winchester uses a 0.4004″ (10.17 mm) diameter bullet.

Is .38-40 Winchester still in production?

.38-40 Winchester is active; typical availability is common.

What is .38-40 Winchester used for?

.38-40 Winchester is primarily used for cowboy action, self-defense.

What is .38-40 Winchester based on?

.38-40 Winchester is derived from the .44-40 Winchester case.

What are the best powders for .38-40 Winchester?

Reloading powders commonly listed for .38-40 Winchester include No. 2, Bull's-Eye, Universal, HP-38, among 5 suitable options.

Lindcott Armory

Pistol · SAAMI

.38-40 Winchester

Also known as .38 WCF · .38-40 WCF · 38-40

A cowboy-era dual-use cartridge chambered in both Winchester rifles and Colt revolvers.

Caliber: 0.4004″ · 10.17 mm
Introduced: 1874
Case: Rimmed
Parent: .44-40 Winchester
Primary use: Cowboy Action, Self-Defense
Status: Active

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VelocityBeing verified

EnergyBeing verified

Typical grains180 gr

Identity

Introduced: 1874
Type: Pistol
Origin: United States
Inventor: Winchester
Manufacturer: Winchester Repeating Arms
Standard: SAAMI
Status: Active
Availability: Common

Build

Case capacity: 40 gr H₂O
Twist (typical): 1:36
Primer: Large Pistol
Case type: Rimmed

Pressure & range

Max pressure: 14,000 psi
Eff. range: 50 yd
Max range: 300 yd
Recoil: 3.5–5.5 ft·lb
Subsonic: Capable

Introduced by Winchester Repeating Arms

Ballistics

Published velocity/energy data isn't available for .38-40 Winchester. Parent case: .44-40 Winchester.

Performance

Best for Withheld until verified

Dimensionscase measurements · scale drawing · size vs familiar rounds

Case dimensions — the scale drawing at the top of the page is built from these.

CIP TDCC · verified

Measure	mm	in	✓
Bullet ⌀	10.17	0.400	✓
Neck ⌀	10.58	0.417	✓
Shoulder ⌀	11.54	0.454	✓
Shoulder angle	6.8°	—	✓
Base ⌀	11.93	0.470	✓
Rim ⌀	13.34	0.525	✓
Belt ⌀	n/a
Rim thickness	1.65	0.065	✓
Neck length	5.87	0.231	≈
Case length	33.15	1.305	✓
Overall length	40.44	1.592	✓

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. .38-40 Winchester is highlighted below.

Factory loads

Verification

Being verified

Advertised FPS, energy, and BC are withheld until loads clear verification.

Suitable powders

5 reloading powders listed for .38-40 Winchester, fastest to slowest. Cross-reference in the finder →

Reloading costestimate cost per round vs factory

Estimate your cost per round and how it compares to factory. Inputs are yours — nothing is stored.

Powder $/lb Charge (gr) Bullet $/ea Primer $/ea Brass reuses Brass $/ea

Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.

Firearms chambered in .38-40 Winchester

12 models in the database chamber .38-40 Winchester. Browse all →

Marlin Firearms Model 1894 .38-40 Win 20-inchHenry Repeating Arms Henry Big Boy .38-40 Win 20-inchRuger New Vaquero .357 Mag 4.62-inchCimarron Firearms Doc Holliday .45 Colt 3.5-inchRuger Blackhawk .357 Mag/.38-40 ConvertibleUberti Schofield 2nd ModelRuger Vaquero .357 Mag 5.5-inch OriginalPietta 1873 SAA .38-40 Win 4.75-inchCimarron Firearms Cimarron Model P .45 Colt 7.5-inchCimarron Firearms Cimarron Frontier .45 Colt 4.75-inchCimarron Firearms Model 1873 .45 ColtTaylor's & Company 1873 Gunfighter .45 Colt 4.75-inch

Lineage

Family TreeOpen .38-40 Winchester in the interactive cartridge family tree

Connected reference

Loads37 factory loads for .38-40 Winchester Reloading5 suitable powders — cross-reference FirearmsFirearms in .38-40 Winchester

History

The second in Winchester's rifle-revolver cartridge series (after .44-40). The '38' in the name refers to the case mouth diameter, not bullet size — it fires .401" bullets. Became the preferred cartridge of many lawmen and outlaws who wanted one ammunition type for both rifle and revolver.

FAQs

What twist rate does .38-40 Winchester use?: .38-40 Winchester typically uses a 1:36 twist rate.
What bullet diameter is .38-40 Winchester?: .38-40 Winchester uses a 0.4004″ (10.17 mm) diameter bullet.
Is .38-40 Winchester still in production?: .38-40 Winchester is active; typical availability is common.
What is .38-40 Winchester used for?: .38-40 Winchester is primarily used for cowboy action, self-defense.
What is .38-40 Winchester based on?: .38-40 Winchester is derived from the .44-40 Winchester case.
What are the best powders for .38-40 Winchester?: Reloading powders commonly listed for .38-40 Winchester include No. 2, Bull's-Eye, Universal, HP-38, among 5 suitable options.

Sources & provenance

Standard SAAMI — SAAMI cartridge & chamber drawing — .38-40 Winchester archived
Standard C.I.P. — C.I.P. TDCC — Tables of Dimensions of Cartridges and Chambers
Standard SAAMI — ANSI/SAAMI Z299.4-2025 — Centerfire Rifle Velocity & Pressure Data · grain_ballistics, representative_gun archived
Manufacturer Winchester Ammunition — Super-X Rifle — 44-40 Winchester 200 gr Power-Point (X4440) · grain_ballistics, representative_gun archived
Manufacturer Black Hills Ammunition — .38-40 — Authentic Cowboy Action · grain_ballistics, representative_gun archived

Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 32 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →