Rifle · Obsolete / Non-standard
.256 Newton
Early high-velocity American 6.5 mm sporting cartridge (essentially a "6.5-06")..
- Caliber
- 0.264″ · 6.706 mm
- Introduced
- 1913
- Case
- Rimless
- Parent
- .30-06 Springfield
- Primary use
- Hunting, Target
- Status
- Obsolete
- Introduced
- 1913
- Type
- Rifle
- Origin
- United States
- Inventor
- Charles Newton
- Manufacturer
- Newton Arms
- Standard
- Obsolete / Non-standard
- Status
- Obsolete
- Availability
- Collector
- Primer
- Large Rifle
- Case type
- Rimless
- Eff. range
- 300 yd
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for .256 Newton, 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
- .30-06 Springfield
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 ⌀ | 6.71 | 0.264 | · |
| Neck ⌀ | 7.39 | 0.291 | · |
| Shoulder ⌀ | 10.62 | 0.418 | · |
| Shoulder angle | 23° | — | ~ |
| Base ⌀ | 11.96 | 0.471 | · |
| Rim ⌀ | 12.01 | 0.473 | · |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.25 | 0.049 | · |
| Neck length | 7.37 | 0.290 | ≈ |
| Case length | 61.98 | 2.440 | ~ |
| Overall length | 86.36 | 3.400 | · |
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. .256 Newton is highlighted below.
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.
Lineage
Connected reference
History
Introduced 1913 by Charles Newton; formed from the .30-06 case necked to 6.5 mm — NOT derived from the larger .30 Newton case.
FAQs
- What bullet diameter is .256 Newton?
- .256 Newton uses a 0.264″ (6.706 mm) diameter bullet.
- Is .256 Newton still in production?
- .256 Newton is obsolete; typical availability is collector.
- What is .256 Newton used for?
- .256 Newton is primarily used for hunting, target.
- What is .256 Newton based on?
- .256 Newton is derived from the .30-06 Springfield case.
Sources & provenance
- Reference Frank C. Barnes / Gun Digest — Cartridges of the World, 17th ed. (excerpted as 'Ammo Brief: .256 Newton') · year, bullet ⌀, grain weights, velocity archived
- Secondary Wikipedia — .256 Newton · 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 →