Lindcott Armory Rifle · SAAMI
.257 Weatherby Magnum
Extremely fast and flat-shooting magnum.
- Caliber
- 0.257″ · 6.528 mm
- Introduced
- 1944
- Case
- Belted
- Parent
- .375 H&H Magnum
- Primary use
- Hunting, Varmint
- Status
- Active
- Introduced
- 1944
- Type
- Rifle
- Origin
- United States
- Inventor
- Roy Weatherby
- Manufacturer
- Weatherby
- Standard
- SAAMI
- Status
- Active
- Availability
- Moderate
- Case capacity
- 82 gr H₂O
- Twist (typical)
- 1:10
- Primer
- Large Rifle Magnum
- Case type
- Belted
- Max pressure
- 65,000 psi
- Eff. range
- 500 yd
- Max range
- 4500 yd
- Recoil
- 16–22 ft·lb
Ballistics
Real trajectory computed from a representative load — Underwood Ammo ELD-X 110 gr, 3,450 fps, BC 0.241 G7 · 100 yd zero.
| Range | Velocity | Energy | Drop (in) | Drop (MOA) |
|---|---|---|---|---|
| 0 yd | 3449 | 2905 | -1.5″ | — |
| 100 yd | 3241 | 2565 | 0.0″ | 0.0 |
| 200 yd | 3039 | 2255 | -1.9″ | -0.9 |
| 300 yd | 2843 | 1974 | -7.5″ | -2.4 |
| 400 yd | 2654 | 1720 | -17.5″ | -4.2 |
| 500 yd | 2471 | 1491 | -32.4″ | -6.2 |
| 600 yd | 2295 | 1287 | -53.0″ | -8.4 |
| 700 yd | 2127 | 1105 | -80.1″ | -10.9 |
| 800 yd | 1964 | 942 | -115.1″ | -13.7 |
| 900 yd | 1808 | 798 | -158.9″ | -16.9 |
| 1000 yd | 1657 | 670 | -213.6″ | -20.4 |
Point-mass G7/G1 drag model, standard atmosphere — within ~2% of reference solvers to 1000 yd; real barrels and conditions vary. Open in Ballistic Compare →
Performance
Buy links open .257 Weatherby Magnum ammunition at Rivertown Munitions.
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 ⌀ | 6.53 | 0.257 | ✓ |
| Neck ⌀ | 7.19 | 0.283 | ✓ |
| Shoulder ⌀ | 12.50 | 0.492 | ✓ |
| Shoulder angle | 25.5° | — | ~ |
| Base ⌀ | 13.01 | 0.512 | ✓ |
| Rim ⌀ | 13.50 | 0.531 | ✓ |
| Belt ⌀ | 13.49 | 0.531 | ✓ |
| Rim thickness | 1.30 | 0.051 | ✓ |
| Neck length | 8.13 | 0.320 | ≈ |
| Case length | 64.64 | 2.545 | ✓ |
| Overall length | 81.51 | 3.209 | ✓ |
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. .257 Weatherby Magnum is highlighted below.
Factory loads
In production — 43 active loads across 14 brands. Top 15 shown · see all 45 →.
| Brand | Load | Grain | Bullet | FPS | ft·lb | BC |
|---|---|---|---|---|---|---|
| Weatherby | Select Plus Barnes TTSX 100gr | 100 | TTSX BT | 3,825 | 3,248 | 0.147 G7 |
| Barnes | VOR-TX TTSX BT 100gr | 100 | TTSX BT | 3,825 | 3,248 | 0.147 G7 |
| Barnes | VOR-TX TTSX BT | 100 | TTSX BT | 3,750 | 3,122 | 0.147 G7 |
| Barnes | VOR-TX | 100 | TTSX | 3,700 | 3,039 | 0.147 G7 |
| DoubleTap | DPX | 100 | TSX | 3,700 | 3,039 | 0.147 G7 |
| Weatherby | Select Plus Barnes TTSX | 100 | TTSX BT | 3,603 | 2,882 | 0.147 G7 |
| Weatherby | Select Plus | 100 | Nosler Ballistic Tip | 3,602 | 2,880 | 0.197 G7 |
| Hornady | Precision Hunter ELD-X 110gr | 110 | ELD-X | 3,550 | 3,078 | 0.241 G7 |
| Nosler | Trophy Grade AccuBond 110gr | 110 | AccuBond | 3,550 | 3,078 | 0.217 G7 |
| DoubleTap | DT Hunter | 100 | Barnes TTSX | 3,500 | 2,720 | 0.147 G7 |
| Weatherby | Select Plus | 110 | Hornady ELD-X | 3,500 | 2,992 | 0.241 G7 |
| Hornady | Precision Hunter | 110 | ELD-X | 3,500 | 2,992 | 0.241 G7 |
| Hornady | Precision Hunter ELD-X | 110 | ELD-X | 3,460 | 2,924 | 0.241 G7 |
| Underwood Ammo | ELD-X | 110 | ELD-X | 3,450 | 2,907 | 0.241 G7 |
| Hornady | ELD-X | 110 | ELD-X | 3,450 | 2,907 | 0.241 G7 |
Velocities are manufacturer-stated (test-barrel). Discontinued loads dimmed.
Suitable powders
2 reloading powders listed for .257 Weatherby Magnum, 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.
Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.
Firearms chambered in .257 Weatherby Magnum
12 models in the database chamber .257 Weatherby Magnum. Browse all →
Lineage
Connected reference
History
Developed by Roy Weatherby in 1944 as his first commercial magnum cartridge. Based on blown-out .375 H&H case necked to .257. Weatherby's personal favorite cartridge. Delivers high muzzle velocity and a flat trajectory. Popular with western hunters and long-range shooters. Heavy recoil for a .25 caliber and significant barrel wear, but dramatic performance.
FAQs
- What twist rate does .257 Weatherby Magnum use?
- .257 Weatherby Magnum typically uses a 1:10 twist rate.
- What bullet diameter is .257 Weatherby Magnum?
- .257 Weatherby Magnum uses a 0.257″ (6.528 mm) diameter bullet.
- Is .257 Weatherby Magnum still in production?
- .257 Weatherby Magnum is active; typical availability is moderate.
- What is .257 Weatherby Magnum used for?
- .257 Weatherby Magnum is primarily used for hunting, varmint.
- What is .257 Weatherby Magnum based on?
- .257 Weatherby Magnum is derived from the .375 H&H Magnum case.
- What are the best powders for .257 Weatherby Magnum?
- Reloading powders commonly listed for .257 Weatherby Magnum include N170, Reloader 25.
Sources & provenance
- StandardSAAMI — SAAMI cartridge & chamber drawing — .257 Weatherby Magnum
- StandardSAAMI — ANSI/SAAMI Z299 — Cartridge & Chamber Drawingsarchived
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 43 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →