The CONTOUR #5 6MM10CM5 is the Douglas 6mm 1-10 Twist CM #5 Contour Ultra Rifled Barrel, a match-grade barrel blank built for shooters and gunsmiths who refuse to compromise on precision. Part of the legendary Douglas Double XX line, this 6mm (.243) chrome moly #5 contour barrel is button-rifled, stress-relieved, and held to extremely tight tolerances—making it an outstanding foundation for your next custom or rebarrel project. Brownells Österreich+1
If you’re building a serious .243/6mm precision hunting rifle, varmint gun, or competition rig, the 6MM10CM5 gives you the accuracy pedigree and material quality you need for long-range confidence.
Douglas Double XX – Premium Ultra Rifled Barrel Blank
Douglas has been building barrels for decades, and their Double XX Ultra Rifled line is famous for accuracy and craftsmanship:
Button rifled for exceptional bore smoothness, which helps reduce fouling and promotes consistent velocities. Primary Tactical+2Brownells+2
Tolerances for groove diameter and straightness held to about 0.0005", supporting repeatable precision when properly chambered and fitted. Primary Tactical+2Brownells+2
Stress-relieved after rifling to minimize internal stresses that can cause point-of-impact shifts as the barrel heats. Brownells+1
6-groove rifling for calibers from .22 through .338, including this 6mm blank—an accuracy-proven configuration used in countless custom rifles. Brownells+1
These details are why Douglas Double XX barrels are consistently recommended for high-accuracy rebarreling projects.
6mm (.243) Caliber with 1:10 Twist – Versatile Bullet Stability
The 6MM10CM5 barrel blank is configured for 6mm/.243 caliber cartridges with a 1:10" twist rate: friscoguns.com+1
A 1:10 twist is a highly useful choice for many 6mm hunting and varmint bullets, providing excellent stability across a wide range of popular projectile weights, depending on cartridge and load:
Light to mid-weight varmint and predator bullets for high-velocity .243-based loads.
Common hunting bullets used in cartridges like .243 Winchester or 6mm Remington when properly chambered by a gunsmith.
This twist rate balances versatility and performance for general-purpose and hunting-oriented 6mm builds.
4140 Chrome Moly Steel – Strong, Durable, and Finish-Friendly
This Douglas barrel blank is made from 4140 chrome moly steel, a proven material for real-world rifles: Primary Tactical+2Brownells+2
Chrome moly construction offers excellent strength and toughness under repeated firing.
Ideal for traditional finishes such as bluing, Parkerizing, or modern coatings like Cerakote once machining is complete.
Designed for long service life with proper care—perfect for a hard-use hunting rifle or working precision rig.
If you prefer the classic feel and look of steel with premium durability, chrome moly is a trusted choice.
#5 Contour – Balanced for Accuracy & Field Use
The #5 contour provides a medium-heavy profile that balances stiffness with practicality: Brownells+2Douglas Barrels Inc.+2
Contour: #5 – heavier than lightweight sporter profiles, offering more rigidity and better heat management.
Retailers list a weight of roughly 4.1 lb for this contour in 6mm chrome moly. friscoguns.com
Well-suited for:
Precision hunting rifles that might see longer shot strings.
Varmint, predator, or target rifles where you want accuracy without the excessive mass of a bull barrel.
For shooters who want a rifle they can still carry in the field—without giving up the benefits of a heavier, more stable barrel—the #5 contour hits a sweet spot.
Ultra Rifled, Stress-Relieved – Built for Match-Grade Accuracy
The Ultra Rifled designation reflects Douglas’s attention to the internal finish and consistency of their bores:
Button rifled for a smooth internal surface that cleans easier and fouls less. Brownells+2Brownells Deutschland+2
No post-rifling straightening—Douglas relies on carefully controlled manufacturing and stress relief instead of forcing barrels straight, helping preserve uniformity. Brownells+1
Fully stress-relieved, which contributes to stable point-of-impact even as barrel temperatures rise during extended strings of fire. Primary Tactical+2Brownells+2
Properly chambered and crowned by a qualified gunsmith, these characteristics let the CONTOUR #5 6MM10CM5 deliver the kind of precision that Douglas Double XX is known for.
Barrel Blank – Unchambered, Not Threaded or Crowned
The CONTOUR #5 6MM10CM5 is sold as an unchambered barrel blank, ready for custom machining: Primary Tactical+2Brownells+2
Not threaded, not chambered, not crowned – gives your gunsmith full control over length, chambering, and muzzle treatment.
Intended for professional fitting to your specific action, cartridge, and application.
Suitable for popular 6mm/.243-based cartridges (such as .243 Win, 6mm Rem, and others) when properly chambered and headspaced by a competent gunsmith.
This blank format is ideal for custom builds and serious rebarrel projects, where every detail is tailored to your exact needs.
Ideal Applications for the 6MM10CM5 #5 Contour Barrel
Thanks to its contour, twist rate, and caliber, this Douglas barrel blank is an excellent platform for:
Precision hunting rifles – optimized for medium game at extended ranges.
Varmint and predator rifles – perfect for high-volume shooting on small targets where heat control and accuracy matter.
General-purpose 6mm builds – ranging from range rifles to steel match guns built around .243-class cartridges.
Whether you’re modernizing a classic action or building from scratch, this barrel gives you match-grade potential in a practical, field-usable contour.
Key Specifications – CONTOUR #5 6MM10CM5
From Douglas and major distributor listings: Brownells Sverige+3friscoguns.com+3Brownells+3
Manufacturer: Douglas
Line: Double XX Ultra Rifled
Model / MFR Part #: 6MM10CM5
Product Name: 6mm 1-10 Twist CM #5 Contour Ultra Rifled Barrel
Caliber: 6mm / .243"
Twist Rate: 1:10"
Material: 4140 Chrome Moly Steel
Rifling Style: Ultra Rifled, button rifled, stress-relieved
Grooves: 6 (for .22–.338 calibers)
Contour: #5
Approx. Weight: ~4.10 lb (finished #5 CM barrel) friscoguns.com
Configuration: Barrel blank – unthreaded, unchambered, uncrowned (gunsmith installation required)
Exact finished length and profile at the muzzle will depend on the final machining and cut length chosen by your gunsmith.
Why Choose the Douglas CONTOUR #5 6MM10CM5 Barrel Blank?
You should consider this barrel blank if you:
Want a match-grade 6mm/.243 barrel from a respected maker with decades of proven performance.
Prefer a #5 contour that offers excellent stiffness and heat resistance while remaining carryable in the field.
Need a 1:10 twist that works well with common 6mm bullet weights for hunting, varminting, and precision shooting.
Value 4140 chrome moly steel and the Douglas Double XX Ultra Rifled pedigree—button rifled, stress-relieved, and held to extremely tight tolerances.
For gunsmiths, custom builders, and accuracy-focused shooters, the CONTOUR #5 6MM10CM5 – Douglas 6mm 1-10 Twist CM #5 Contour Ultra Rifled Barrel is a rock-solid starting point for your next high-performance rifle.
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