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Lindcott Armory

Rifle · Wildcat

6mm Dasher

Also known as 6 Dasher · 6BR Improved · 6mm BR Dasher

Wildcat improvement of 6mm BR Norma with a sharper 40-degree shoulder, optimized for F-Class and precision bolt-gun competition.

Caliber
0.2429″ · 6.17 mm
Introduced
1999
Case
Rimless
Parent
6mm BR Norma
Primary use
Competition, Target
Status
Active

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VelocityBeing verified
EnergyBeing verified
Typical grains105 · 107 · 108 gr
Identity
Introduced
1999
Type
Rifle
Origin
United States
Inventor
Dan Dowling / Lou Murdica
Manufacturer
Custom / Various
Standard
Wildcat
Status
Active
Availability
Limited
Build
Case capacity
38 gr H₂O
Twist (typical)
1:7.5
Primer
Small Rifle
Case type
Rimless
Pressure & range
Max pressure
58,000 psi
Eff. range
1000 yd
Max range
3000 yd
Recoil
5–8 ft·lb

Ballistics

Published velocity/energy data isn't available for 6mm Dasher. Parent case: 6mm BR Norma.

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.

CIP TDCC · verified
Measuremmin
Bullet ⌀ 6.170.243
Neck ⌀ 6.900.272
Shoulder ⌀ 11.650.459
Shoulder angle 40°
Base ⌀ 11.960.471
Rim ⌀ 12.010.473
Belt ⌀ n/a
Rim thickness 1.370.054
Neck length 6.040.238
Case length 39.241.545
Overall length 60.002.362

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. 6mm Dasher 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 6mm Dasher, 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 6mm Dasher

2 models in the database chamber 6mm Dasher. Browse all →

Kelbly's Atlas TacticalKelbly Kelbly Atlas Tactical 6 Dasher 28-inch

Lineage

Immediate parent
Direct descendants (1)
Family TreeOpen 6mm Dasher in the interactive cartridge family tree

Connected reference

History

Created around 1999 by F-Class competitors Dan Dowling and Lou Murdica by fire-forming 6mm BR Norma brass to a sharper shoulder angle. The improved case geometry reduces powder column movement and slightly increases capacity, resulting in more consistent velocities and tighter standard deviations — the holy grail for long-range competition. It dominated F-Open and F-TR competition for years and remains one of the most inherently accurate cartridges ever developed. Never submitted to SAAMI due to the handloading culture of its user base; factory ammunition is available from a handful of small manufacturers.

FAQs

What twist rate does 6mm Dasher use?
6mm Dasher typically uses a 1:7.5 twist rate.
What bullet diameter is 6mm Dasher?
6mm Dasher uses a 0.2429″ (6.17 mm) diameter bullet.
Is 6mm Dasher still in production?
6mm Dasher is active; typical availability is limited.
What is 6mm Dasher used for?
6mm Dasher is primarily used for competition, target.
What is 6mm Dasher based on?
6mm Dasher is derived from the 6mm BR Norma case.
What are the best powders for 6mm Dasher?
Reloading powders commonly listed for 6mm Dasher include N135, LT-32.

Sources & provenance

Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 23 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →