What twist rate does 6.5-300 Weatherby Magnum use?

6.5-300 Weatherby Magnum typically uses a 1:8 twist rate.

What bullet diameter is 6.5-300 Weatherby Magnum?

6.5-300 Weatherby Magnum uses a 0.264″ (6.706 mm) diameter bullet.

Is 6.5-300 Weatherby Magnum still in production?

6.5-300 Weatherby Magnum is active; typical availability is specialty.

What is 6.5-300 Weatherby Magnum used for?

6.5-300 Weatherby Magnum is primarily used for hunting, target.

What is 6.5-300 Weatherby Magnum based on?

6.5-300 Weatherby Magnum is derived from the .300 Weatherby Magnum case.

What are the best powders for 6.5-300 Weatherby Magnum?

Reloading powders commonly listed for 6.5-300 Weatherby Magnum include N170, Reloader 25, Reloader 26, IMR 7977, among 8 suitable options.

Lindcott Armory

Rifle · SAAMI

6.5-300 Weatherby Magnum

Also known as 6.5-300 Wby Mag · 6.5x300 Weatherby · 6.5-300 Weatherby

The fastest commercial 6.5mm cartridge ever produced.

Caliber: 0.264″ · 6.706 mm
Introduced: 2016
Case: Belted
Parent: .300 Weatherby Magnum
Primary use: Hunting, Target
Status: Active

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VelocityBeing verified

EnergyBeing verified

Typical grains127 · 130 · 140 gr

Identity

Introduced: 2016
Type: Rifle
Origin: United States
Inventor: Weatherby
Manufacturer: Weatherby
Standard: SAAMI
Status: Active
Availability: Specialty

Build

Case capacity: 115 gr H₂O
Twist (typical): 1:8
Primer: Large Rifle Magnum
Case type: Belted

Pressure & range

Max pressure: 65,000 psi
Eff. range: 800 yd
Max range: 2000 yd
Recoil: 6–9 ft·lb

Introduced by Weatherby

Ballistics

Published velocity/energy data isn't available for 6.5-300 Weatherby Magnum. Parent case: .300 Weatherby Magnum.

Performance

Best for Withheld until verified

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 ⌀	7.49	0.295	✓
Shoulder ⌀	12.57	0.495	✓
Shoulder angle	—	—
Base ⌀	13.00	0.512	✓
Rim ⌀	13.50	0.531	✓
Belt ⌀	13.50	0.531	✓
Rim thickness	1.30	0.051	~
Neck length	7.61	0.300	≈
Case length	71.76	2.825	✓
Overall length	91.44	3.600	✓

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. 6.5-300 Weatherby Magnum is highlighted below.

Missing a dimension for 6.5-300 Weatherby Magnum? 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.

Factory loads

Verification

Being verified

Advertised FPS, energy, and BC are withheld until loads clear verification.

Suitable powders

8 reloading powders listed for 6.5-300 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.

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.

Firearms chambered in 6.5-300 Weatherby Magnum

12 models in the database chamber 6.5-300 Weatherby Magnum. Browse all →

Weatherby Mark V Terramark RC 6.5-300 Wby MagWeatherby Mark V Backcountry 6.5-300 Wby MagWeatherby Mark V Backcountry Ti .300 Wby MagWeatherby Mark V Camilla Wilderness 6.5-300 Wby MagWeatherby Mark V Backcountry .300 Win MagWeatherby Mark V Backcountry 6.5-300 WbyWeatherby Mark V Backcountry .257 Wby MagWeatherby Mark V Carbon .257 Wby MagWeatherby Mark V Carbon .300 Wby MagFierce Arms CT Edge 300 Win MagWeatherby Mark V 6.5-300 Wby Mag Accumark RCWeatherby Mark V Accumark RC

Lineage

Family TreeOpen 6.5-300 Weatherby Magnum in the interactive cartridge family tree

Connected reference

Loads13 factory loads for 6.5-300 Weatherby Magnum Reloading8 suitable powders — cross-reference FirearmsFirearms in 6.5-300 Weatherby Magnum

History

Weatherby introduced the 6.5-300 in 2016 to ride the 6.5mm wave sweeping the precision rifle market. Their approach was characteristically Weatherby: take the largest viable case and neck it to 6.5mm. The result is dramatically faster than 6.5 Creedmoor, 6.5 PRC, and even .26 Nosler. The flat trajectory and high BC of 6.5mm bullets combine with Weatherby velocity to produce a long-range hunting cartridge of exceptional reach. The cost is barrel life — at these velocities, throat erosion is aggressive, and many owners report 1,000–1,500 round barrel life. For hunters who shoot a few hundred rounds per year, this is irrelevant. Weatherby chambers the Mark V exclusively.

FAQs

What twist rate does 6.5-300 Weatherby Magnum use?: 6.5-300 Weatherby Magnum typically uses a 1:8 twist rate.
What bullet diameter is 6.5-300 Weatherby Magnum?: 6.5-300 Weatherby Magnum uses a 0.264″ (6.706 mm) diameter bullet.
Is 6.5-300 Weatherby Magnum still in production?: 6.5-300 Weatherby Magnum is active; typical availability is specialty.
What is 6.5-300 Weatherby Magnum used for?: 6.5-300 Weatherby Magnum is primarily used for hunting, target.
What is 6.5-300 Weatherby Magnum based on?: 6.5-300 Weatherby Magnum is derived from the .300 Weatherby Magnum case.
What are the best powders for 6.5-300 Weatherby Magnum?: Reloading powders commonly listed for 6.5-300 Weatherby Magnum include N170, Reloader 25, Reloader 26, IMR 7977, among 8 suitable options.

Sources & provenance

Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 13 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →