Rifle · Wildcat
6XC
David Tubb's competition wildcat: a mid-size 6mm case optimized for long-range F-Open competition, offering more powder capacity than 6mm BR while staying shorter than 6-284..
- Caliber
- 0.2429″ · 6.17 mm
- Introduced
- 2005
- Case
- Rebated
- Parent
- .250 Savage
- Primary use
- Competition, Target
- Status
- Active
- Introduced
- 2005
- Type
- Rifle
- Origin
- United States
- Inventor
- David Tubb
- Manufacturer
- Superior Shooting Systems
- Standard
- Wildcat
- Status
- Active
- Availability
- Limited
- Case capacity
- 62 gr H₂O
- Twist (typical)
- 1:8
- Primer
- Large Rifle
- Case type
- Rebated
- Max pressure
- 62,000 psi
- Eff. range
- 1000 yd
- Max range
- 2500 yd
- Recoil
- 5–8 ft·lb
Ballistics
Published velocity/energy data isn't available for 6XC. Parent case: .284 Winchester.
Performance
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| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 6.17 | 0.243 | ✓ |
| Neck ⌀ | 6.82 | 0.269 | ✓ |
| Shoulder ⌀ | 11.42 | 0.450 | ✓ |
| Shoulder angle | 30° | — | ✓ |
| Base ⌀ | 11.84 | 0.466 | ✓ |
| Rim ⌀ | 11.86 | 0.467 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.22 | 0.048 | ✓ |
| Neck length | 7.49 | 0.295 | ≈ |
| Case length | 48.10 | 1.894 | ✓ |
| Overall length | 63.40 | 2.496 | ✓ |
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. 6XC is highlighted below.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
Suitable powders
12 reloading powders listed for 6XC, 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.
Lineage
Connected reference
History
Developed around 2005 by David Tubb, 12-time National High Power champion. The 6XC was engineered specifically for F-Open and High Power competition, bridging the gap between the efficient but small 6mm BR and the larger but over-powered 6-284. Superior Shooting Systems (Tubb's company) produces custom brass. The cartridge won numerous national and world titles in F-Open competition throughout the late 2000s and 2010s. Never submitted to SAAMI — its handloading-focused user base preferred it stay a wildcat.
FAQs
- What twist rate does 6XC use?
- 6XC typically uses a 1:8 twist rate.
- What bullet diameter is 6XC?
- 6XC uses a 0.2429″ (6.17 mm) diameter bullet.
- Is 6XC still in production?
- 6XC is active; typical availability is limited.
- What is 6XC used for?
- 6XC is primarily used for competition, target.
- What is 6XC based on?
- 6XC is derived from the .284 Winchester case.
- What are the best powders for 6XC?
- Reloading powders commonly listed for 6XC include IMR 3031, N135, N550, 203-B, among 12 suitable options.
Sources & provenance
- Standard SAAMI — SAAMI cartridge & chamber drawing — 6XC archived
- Standard C.I.P. — C.I.P. TDCC — Tables of Dimensions of Cartridges and Chambers
- Secondary 6 mm XC - Wikipedia · parent_cartridge
- Secondary 6XC Cartridge Guide - AccurateShooter · parent_cartridge
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 20 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →