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Lindcott Armory

Rifle · SAAMI

.277 Fury

Also known as 6.8x51mm · 6.8 Common Cartridge · 6.8 NGSW · 6.8x51mm Common Cartridge

The US Army's Next Generation Squad Weapon (NGSW) cartridge — the first new US military rifle cartridge since 5.56mm NATO.

Caliber
0.278″ · 7.061 mm
Introduced
2022
Case
Rimless
Primary use
Military, Hunting, Target
Status
Active

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VelocityBeing verified
EnergyBeing verified
Typical grains130 · 140 · 150 gr
Identity
Introduced
2022
Type
Rifle
Origin
United States
Inventor
SIG Sauer / US Army
Manufacturer
SIG Sauer, Olin/Winchester
Standard
SAAMI
Status
Active
Availability
Limited
Build
Case capacity
77 gr H₂O
Twist (typical)
1:8
Primer
Large Rifle
Case type
Rimless
Pressure & range
Max pressure
80,000 psi
Eff. range
800 yd
Max range
1500 yd
Recoil
20–30 ft·lb

Ballistics

Published velocity/energy data isn't available for .277 Fury.

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.

SAAMI · verified
Measuremmin
Bullet ⌀ 7.060.278
Neck ⌀ 7.870.310
Shoulder ⌀ 11.710.461
Shoulder angle 30°
Base ⌀ 11.950.470
Rim ⌀ 11.990.472
Belt ⌀ n/a
Rim thickness 1.370.054
Neck length 6.430.253
Case length 51.182.015
Overall length 71.762.825

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. .277 Fury is highlighted below.

Factory loads

Verification

Being verified

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

Suitable powders

2 reloading powders listed for .277 Fury, 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 .277 Fury

12 models in the database chamber .277 Fury. Browse all →

Sig Sauer MCX Spear-LT 6.8Sig Sauer MCX Spear 7.62x51mm 16-inchSIG Sauer SIG MCX Spear 6.8x51mm 16-inchSIG Sauer MCX Spear PistolSig Sauer MCX Spear LT 5.56 NATO 11.5-inchSig Sauer MCX Spear .277 Fury 16-inchSig Sauer MCX Spear 6.8x51mm Semi-AutoSIG Sauer MCX Spear 6.8x51mm 13-inchSIG Sauer MCX Spear 6.8x51mmSIG Sauer MCX Spear-LTSIG Sauer MCX SpearSIG Sauer Cross .277 Fury 16-inch

Connected reference

History

Selected by the US Army in April 2022 as part of the NGSW program to replace the M4/M16 and M249 in frontline units. The driving requirement was defeating current and projected enemy body armor at 600+ meters — a capability gap identified after analysis of near-peer adversary protection. The .277 Fury uses a hybrid case with a steel head and brass body to contain the unprecedented 80,000 PSI operating pressure. SIG Sauer's XM5 rifle and XM250 machine gun were selected. Full fielding to combat units began 2023–2025.

FAQs

What twist rate does .277 Fury use?
.277 Fury typically uses a 1:8 twist rate.
What bullet diameter is .277 Fury?
.277 Fury uses a 0.278″ (7.061 mm) diameter bullet.
Is .277 Fury still in production?
.277 Fury is active; typical availability is limited.
What is .277 Fury used for?
.277 Fury is primarily used for military, hunting, target.
What are the best powders for .277 Fury?
Reloading powders commonly listed for .277 Fury include Reloader 19, Reloader 26.

Sources & provenance

Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 22 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →