What bullet diameter is .25-20 Single Shot?

.25-20 Single Shot uses a 0.257″ (6.528 mm) diameter bullet.

Is .25-20 Single Shot still in production?

.25-20 Single Shot is obsolete; typical availability is collector.

What is .25-20 Single Shot used for?

.25-20 Single Shot is primarily used for target, small game.

What is .25-20 Single Shot based on?

.25-20 Single Shot is derived from the .32 Extra Long case.

Lindcott Armory

Rifle · Obsolete / Non-standard

.25-20 Single Shot

Also known as .25-20 SS · .25-20 Single-Shot · .25-20 Stevens

Long, narrow American single-shot cartridge; parent case for early high-velocity .22 wildcats (R2 Lovell)..

Caliber: 0.257″ · 6.528 mm
Introduced: 1882
Case: Rimmed
Parent: .32 Extra Long
Primary use: Target, Small game
Status: Obsolete

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Velocity1,270–1,580 fps

Energy308–477 ft·lb · est.

Identity

Introduced: 1882
Type: Rifle
Origin: United States
Inventor: J. Francis Rabbeth
Manufacturer: Maynard / J. Stevens (early makers)
Standard: Obsolete / Non-standard
Status: Obsolete
Availability: Collector

Build

Primer: Small Rifle
Case type: Rimmed

Pressure & range

Eff. range: 150 yd

Ballistics

Representative trajectory · velocity only, no drag model · 100 yd zero0–500 yd

Drop Zero

Velocity only, no drag model: no published ballistic coefficient is on file for .25-20 Single Shot, 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: .32 Extra Long

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.

mixed/other · approximate

Measure	mm	in	✓
Bullet ⌀	6.53	0.257	~
Neck ⌀	6.99	0.275	·
Shoulder ⌀	—	—
Shoulder angle	—	—
Base ⌀	8.00	0.315	~
Rim ⌀	9.60	0.378	·
Belt ⌀	n/a
Rim thickness	1.27	0.050	~
Neck length	—	—
Case length	41.40	1.630	·
Overall length	53.47	2.105	·

Missing a dimension for .25-20 Single Shot? Some case measurements aren't in a published SAAMI/CIP drawing yet. Have a factory or reamer print? Send it → — verified hard-to-find data earns a free Lindcott sticker.

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.

Lineage

Family TreeOpen .25-20 Single Shot in the interactive cartridge family tree

Connected reference

FirearmsFirearms in .25-20 Single Shot ToolCompare ballistics

History

Designed by J. Francis Rabbeth, 1882; first chambered by Maynard, then Stevens/Winchester. Distinct from the bottlenecked .25-20 Winchester.

FAQs

What bullet diameter is .25-20 Single Shot?: .25-20 Single Shot uses a 0.257″ (6.528 mm) diameter bullet.
Is .25-20 Single Shot still in production?: .25-20 Single Shot is obsolete; typical availability is collector.
What is .25-20 Single Shot used for?: .25-20 Single Shot is primarily used for target, small game.
What is .25-20 Single Shot based on?: .25-20 Single Shot is derived from the .32 Extra Long case.

Sources & provenance

Reference Frank C. Barnes / Gun Digest — Cartridges of the World · bullet ⌀, grain weights, velocity
Secondary Black Powder Cartridge News — The 25-20 Single Shot · year, grain weights, velocity, 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 →