Rifle · Military · Not SAAMI standardized · Not standardizedObsolete
11mm Beaumont
Black powder military cartridge for the Dutch Beaumont and Beaumont-Vitali repeating rifles; one of the last major military services using a large-bore black powder round..
- Caliber
- 0.4555″ · 11.57 mm
- Introduced
- 1871
- Case
- Rimmed
- Primary use
- Hunting
- Status
- Discontinued
- Obsolete
- Obsolete
- Introduced
- 1871
- Type
- Rifle
- Origin
- Netherlands
- Inventor
- Edouard de Beaumont / Dutch military
- Manufacturer
- Netherlands state arsenals
- Standard
- Military · Not SAAMI standardized · Not standardized
- SAAMI
- Not SAAMI standardized
- Obsolete
- Obsolete
- Status
- Discontinued
- Availability
- Rare
- Case capacity
- 78.2 gr H₂O
- Twist (typical)
- 1:18
- Primer
- Berdan Large Rifle
- Case type
- Rimmed
- Max pressure
- 18,000 psi, CIP transducer
- Eff. range
- 400 yd
- Max range
- 3550 yd
- Recoil
- 19.6–21.6 ft·lb
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for 11mm Beaumont, 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
- —
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.
SAAMI · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 11.57 | 0.456 | · |
| Neck ⌀ | 11.92 | 0.469 | ~ |
| Shoulder ⌀ | 13.57 | 0.534 | |
| Shoulder angle | 15° | — | |
| Base ⌀ | 14.61 | 0.575 | · |
| Rim ⌀ | 16.66 | 0.656 | ~ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.50 | 0.059 | ~ |
| Neck length | 11.94 | 0.470 | |
| Case length | 50.97 | 2.007 | · |
| Overall length | 64.08 | 2.523 | · |
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. 11mm Beaumont is highlighted below.
Missing a dimension for 11mm Beaumont? 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.
Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.
Firearms chambered in 11mm Beaumont
Connected reference
History
Adopted in 1871 for the Dutch Beaumont single-shot rifle, and later used in the Beaumont-Vitali 8-round tubular magazine conversion. The Netherlands was one of the last major powers to field large-bore black powder military rifles before the transition to small-bore smokeless cartridges.
FAQs
- What twist rate does 11mm Beaumont use?
- 11mm Beaumont typically uses a 1:18 twist rate.
- What bullet diameter is 11mm Beaumont?
- 11mm Beaumont uses a 0.4555″ (11.57 mm) diameter bullet.
- Is 11mm Beaumont still in production?
- 11mm Beaumont is discontinued; typical availability is rare.
- What is 11mm Beaumont used for?
- 11mm Beaumont is primarily used for hunting.
Sources & provenance
- Reference Gun Digest Books — Cartridges of the World (Frank C. Barnes) — 11mm Beaumont (Dutch, .43 Beaumont) · grain weights, velocity, bullet ⌀, year
- Secondary militaryrifles.com — M1871 & M1871/79 Beaumont · velocity, bullet ⌀, year 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 →
