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Lindcott Armory

Rifle · Proprietary

.50 Beowulf

Also known as 12.7x42mm

Big-bore AR-15 cartridge for hunting and close-range stopping power.

Caliber
0.5″ · 12.7 mm
Introduced
2001
Case
Rebated
Primary use
Hunting, Self Defense
Status
Active

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VelocityBeing verified
EnergyBeing verified
Typical grains300 · 325 · 400 gr
Identity
Introduced
2001
Type
Rifle
Origin
United States
Inventor
Bill Alexander
Manufacturer
Alexander Arms
Standard
Proprietary
Status
Active
Availability
Moderate
Build
Case capacity
74 gr H₂O
Twist (typical)
1:20
Primer
Large Pistol
Case type
Rebated
Pressure & range
Max pressure
33,000 psi
Eff. range
200 yd
Max range
1500 yd
Recoil
10–16 ft·lb

Introduced by Alexander Arms

Ballistics

Published velocity/energy data isn't available for .50 Beowulf.

Performance

Best for Withheld until verified
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.

Wikipedia · secondary source
Measuremmin✓
Bullet ⌀ 12.700.500 ·
Neck ⌀ 13.340.525 ·
Shoulder ⌀ n/a
Shoulder angle n/a
Base ⌀ 13.590.535 ·
Rim ⌀ 11.300.445 ·
Belt ⌀ n/a
Rim thickness 1.500.059 ~
Neck length n/a
Case length 41.911.650 ·
Overall length 53.982.125 ~

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. .50 Beowulf is highlighted below.

Factory loads

Verification

Being verified

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

Suitable powders

1 reloading powder listed for .50 Beowulf, fastest to slowest. Cross-reference in the finder →

Lil'Gun
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 .50 Beowulf

6 models in the database chamber .50 Beowulf. Browse all →

Bear Creek Arsenal 50 Beowulf 16-inchRadical Firearms 50 Beowulf 16-inchAlexander Arms Beowulf 16-inchAlexander Arms BeowulfAlexander Arms Beowulf .50 BeowulfAlexander Arms 6.8 SPC 16-inch

Connected reference

Loads24 factory loads for .50 BeowulfReloading1 suitable powder — cross-referenceFirearmsFirearms in .50 Beowulf

History

Developed by Bill Alexander in 2001 specifically for AR-15 platform. Named after the legendary warrior Beowulf. Designed to provide big-game hunting power and barrier-penetration capability in AR-15. Uses standard AR-15 bolt face and magazines (though reduced capacity). Popular for hog hunting, home defense, and close-range hunting. Competes with .458 SOCOM and .450 Bushmaster in AR-15 big-bore market.

FAQs

What twist rate does .50 Beowulf use?
.50 Beowulf typically uses a 1:20 twist rate.
What bullet diameter is .50 Beowulf?
.50 Beowulf uses a 0.5″ (12.7 mm) diameter bullet.
Is .50 Beowulf still in production?
.50 Beowulf is active; typical availability is moderate.
What is .50 Beowulf used for?
.50 Beowulf is primarily used for hunting, self defense.
What are the best powders for .50 Beowulf?
Reloading powders commonly listed for .50 Beowulf include Lil'Gun.

Sources & provenance

Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 24 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →