Lindcott Armory Rifle · SAAMI
.300 Weatherby Magnum
Roy Weatherby's flagship cartridge and the one that made his name.
- Caliber
- 0.308″ · 7.823 mm
- Introduced
- 1944
- Case
- Belted
- Parent
- .300 H&H Magnum
- Primary use
- Hunting, Long Range, Big Game
- Status
- Active
- Introduced
- 1944
- Type
- Rifle
- Origin
- United States
- Inventor
- Roy Weatherby
- Manufacturer
- Weatherby
- Standard
- SAAMI
- Status
- Active
- Availability
- Common
- Case capacity
- 99 gr H₂O
- Twist (typical)
- 1:10
- Primer
- Large Rifle Magnum
- Case type
- Belted
- Max pressure
- 65,000 psi
- Eff. range
- 700 yd
- Max range
- 1600 yd
- Recoil
- 35–48 ft·lb
Ballistics
Real trajectory computed from a representative load — Berger Hunting VLD 230 gr, 2,950 fps, BC 0.380 G7 · 100 yd zero.
| Range | Velocity | Energy | Drop (in) | Drop (MOA) |
|---|---|---|---|---|
| 0 yd | 2949 | 4442 | -1.5″ | — |
| 100 yd | 2827 | 4081 | 0.0″ | 0.0 |
| 200 yd | 2707 | 3741 | -2.9″ | -1.4 |
| 300 yd | 2589 | 3422 | -10.5″ | -3.4 |
| 400 yd | 2474 | 3124 | -23.4″ | -5.6 |
| 500 yd | 2361 | 2847 | -41.8″ | -8.0 |
| 600 yd | 2251 | 2588 | -66.7″ | -10.6 |
| 700 yd | 2145 | 2349 | -98.3″ | -13.4 |
| 800 yd | 2041 | 2127 | -137.3″ | -16.4 |
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 .300 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 ⌀ | 7.82 | 0.308 | ✓ |
| Neck ⌀ | 8.56 | 0.337 | ✓ |
| Shoulder ⌀ | 12.50 | 0.492 | ✓ |
| Shoulder angle | 20.6° | — | ~ |
| Base ⌀ | 13.00 | 0.512 | ✓ |
| Rim ⌀ | 13.49 | 0.531 | ✓ |
| Belt ⌀ | 13.50 | 0.531 | ✓ |
| Rim thickness | 1.27 | 0.050 | ~ |
| Neck length | 8.15 | 0.321 | ≈ |
| Case length | 71.75 | 2.825 | ✓ |
| Overall length | 90.42 | 3.560 | ✓ |
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. .300 Weatherby Magnum is highlighted below.
Factory loads
In production — 60 active loads across 21 brands. Top 15 shown · see all 60 →.
| Brand | Load | Grain | Bullet | FPS | ft·lb | BC |
|---|---|---|---|---|---|---|
| Weatherby | Select Plus Barnes TTSX | 165 | TTSX BT | 3,390 | 4,210 | 0.216 G7 |
| Weatherby | Select Plus | 165 | Barnes TTSX | 3,350 | 4,111 | 0.216 G7 |
| Hornady | Superformance | 180 | ELD-X | 3,250 | 4,221 | 0.290 G7 |
| Weatherby | Select Plus | 180 | Nosler Partition | 3,240 | 4,195 | 0.474 G1 |
| Weatherby | Select Plus Nosler AccuBond | 180 | Nosler AccuBond | 3,240 | 4,195 | 0.259 G7 |
| Fiocchi | Extrema | 180 | SST | 3,240 | 4,195 | 0.259 G7 |
| Barnes | VOR-TX | 180 | TTSX | 3,240 | 4,195 | 0.235 G7 |
| Winchester | Expedition Big Game | 180 | Nosler AccuBond | 3,240 | 4,195 | 0.259 G7 |
| Hornady | Precision Hunter ELD-X 178gr | 178 | ELD-X | 3,200 | 4,047 | 0.287 G7 |
| Nosler | Trophy Grade AccuBond 180gr | 180 | AccuBond | 3,190 | 4,067 | 0.259 G7 |
| Barnes | VOR-TX TTSX BT 180gr | 180 | TTSX BT | 3,190 | 4,067 | 0.235 G7 |
| Weatherby | Select Plus AccuBond 180gr | 180 | AccuBond | 3,190 | 4,067 | 0.259 G7 |
| Weatherby | Select Plus Barnes TTSX 180gr | 180 | TTSX BT | 3,190 | 4,067 | 0.235 G7 |
| Weatherby | Select Plus Nosler Partition 180gr | 180 | Partition | 3,190 | 4,067 | 0.474 G1 |
| Black Hills | Gold | 215 | OTM | 3,100 | 4,587 | 0.354 G7 |
Velocities are manufacturer-stated (test-barrel). Discontinued loads dimmed.
Suitable powders
3 reloading powders listed for .300 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 .300 Weatherby Magnum
12 models in the database chamber .300 Weatherby Magnum. Browse all →
Lineage
Connected reference
History
Roy Weatherby developed the cartridge in 1944, a year before formally founding Weatherby Inc. in 1945. The .300 Wby Mag was his calling card. Its double-radius shoulder design reduces case stretching. For decades it was the most powerful commercial .30 caliber cartridge available. Celebrities like John Wayne, Roy Rogers, and Herb Klein hunted with Weatherby rifles.
FAQs
- What twist rate does .300 Weatherby Magnum use?
- .300 Weatherby Magnum typically uses a 1:10 twist rate.
- What bullet diameter is .300 Weatherby Magnum?
- .300 Weatherby Magnum uses a 0.308″ (7.823 mm) diameter bullet.
- Is .300 Weatherby Magnum still in production?
- .300 Weatherby Magnum is active; typical availability is common.
- What is .300 Weatherby Magnum used for?
- .300 Weatherby Magnum is primarily used for hunting, long range, big game.
- What is .300 Weatherby Magnum based on?
- .300 Weatherby Magnum is derived from the .300 H&H Magnum case.
- What are the best powders for .300 Weatherby Magnum?
- Reloading powders commonly listed for .300 Weatherby Magnum include Reloader 19, Alliant Reloader 22, Reloader 26.
Sources & provenance
- StandardSAAMI — SAAMI cartridge & chamber drawing — .300 Weatherby Magnum
- StandardSAAMI — ANSI/SAAMI Z299 — Cartridge & Chamber Drawingsarchived
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 60 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →