The CONTOUR #4 3010CM4 – Douglas .30 1-10 Twist CM #4 Contour Ultra Rifled Barrel is a premium .30 caliber (0.308") chrome moly barrel blank from the legendary Douglas Double XX line. Engineered for serious hunters, precision shooters, and custom rifle builders, this Ultra Rifled #4 contour barrel delivers the accuracy, consistency, and craftsmanship that Douglas is famous for in a versatile, rebarrel-ready package. Brownells UK+1
If you’re planning a .30 caliber rebarreling project—whether for .308 Winchester, .30-06 Springfield, .300 Win Mag (with appropriate chambering) or other .30-cal cartridges—this Douglas 3010CM4 barrel blank is an outstanding starting point for a custom, match-grade rifle.
Douglas Double XX – Premium Ultra Rifled Barrel Blank
This CONTOUR #4 barrel is part of the Douglas Double XX premium-grade series, widely respected in the custom rifle world:
Douglas Double XX barrels are known for proven accuracy and finest care in manufacture. Brownells UK+1
Each barrel is button rifled for exceptional internal smoothness, helping to minimize fouling and promote consistent velocities. Brownells UK+1
Tolerances for groove diameter and straightness are held to approximately 0.0005", supporting precise, repeatable shot placement when properly chambered and fitted. Brownells UK+1
No post-rifling straightening is done—Douglas relies on careful processes and stress relief to maintain bore integrity. All barrels are fully stress-relieved for greater stability as they heat during firing. Brownells UK+1
For gunsmiths and builders who care deeply about the foundation of their rifle’s accuracy, Douglas Double XX barrels are a well-proven choice.
.30 Caliber, 1:10 Twist – Versatile .308 Bore Performance
The 3010CM4 is a .30 caliber barrel blank with a 1:10" twist rate:
A 1:10 twist is a classic, highly versatile choice for .30-caliber rifles:
Handles a wide range of bullet weights, from lighter 150–165 grain deer bullets to heavier 180+ grain hunting or long-range projectiles, depending on cartridge selection and load.
Well-suited for popular hunting and general-purpose .30-cal cartridges, making this blank an excellent foundation for an all-around hunting or precision rifle when professionally chambered.
This twist rate gives you the flexibility to tailor your build to your preferred bullet weights and intended use.
Chrome Moly Steel – Strength & Real-World Durability
The CONTOUR #4 3010CM4 barrel is made from chrome moly (CM) steel, a strong and time-tested barrel material:
Material: Chrome Moly Steel (4140 series, per Douglas contour specs) Brownells UK+1
Chrome moly is known for:
Excellent strength and toughness under repeated firing.
Good machinability, allowing your gunsmith to cut a precise chamber and crown.
Long service life when properly maintained and finished (e.g., blued, Cerakoted, or other protective coatings).
For a working hunting rifle or field-ready precision gun, chrome moly provides a rugged, reliable foundation.
#4 Contour – Perfect Balance of Stiffness and Carry Weight
This barrel blank uses the Douglas #4 contour, a popular mid-weight profile:
The #4 contour offers an ideal compromise:
More stiffness and heat-handling than very light sporter contours, helping maintain point of impact during longer shot strings.
Lighter than heavy varmint or bull barrels, making it practical for carry in the field, mountain hunts, or walking varmint sets.
Great choice for all-around hunting rifles, precision sporters, and multi-purpose builds where you want both accuracy and manageable weight.
If your goal is a rifle that carries well and still shoots like a precision tool, #4 contour is a proven sweet spot.
Ultra Rifled – Smooth, Consistent Bore for Accuracy
Douglas labels this blank as Ultra Rifled, emphasizing high internal quality and consistency:
Button rifled for “unequalled smoothness” in the bore, aiding easy cleaning and reduced fouling. Brownells UK+1
6-groove rifling is used for .22 through .338 calibers (including this .30-cal barrel), offering a traditional, accuracy-proven bore configuration. Brownells UK
Stress-relieved after rifling, reducing internal stresses that can otherwise shift point of impact as the barrel warms up. Brownells UK+1
Properly chambered and crowned by a competent gunsmith, these features help the 3010CM4 deliver the kind of accuracy that Douglas Double XX barrels are known for.
Unchambered Barrel Blank – Built for Custom Rebarreling
The CONTOUR #4 3010CM4 is sold as an unchambered barrel blank, giving your gunsmith maximum flexibility:
Douglas notes that finished barrel dimensions will match the contour chart, while unturned blanks (if supplied in that form) may be slightly oversized in length and diameter, allowing full custom profiling. Primary Tactical+1
All chambering, threading, headspacing, crowning, and finishing must be performed by a qualified gunsmith in accordance with safe practices and applicable laws.
Ideal Applications for the 3010CM4 #4 Contour Barrel
Thanks to its .308 bore, 1:10 twist, and #4 contour, this Douglas barrel blank is perfect for:
Big game hunting rifles – Such as .308 Win or .30-06 builds where dependable accuracy and manageable weight matter.
All-around sporter/precision hybrids – Guns that might see duty on the bench, steel range, or in the deer stand.
Traditional and modern build projects – From classic walnut-stocked rifles to modern synthetic or chassis-based setups.
Whether you’re building a rugged backcountry rifle or a precise whitetail/elk rifle, this blank is versatile enough to support a wide array of .30-cal cartridges and use cases.
Key Specifications – CONTOUR #4 3010CM4
From current distributor and manufacturer listings: Brownells UK+2friscoguns.com+2
Manufacturer: Douglas
Line: Double XX Ultra Rifled Barrel
Model / MFR Part #: 3010CM4
Product Name: .30 1-10 Twist CM #4 Contour Ultra Rifled Barrel
Caliber: .30 caliber (.308")
Twist Rate: 1:10"
Material: Chrome Moly Steel
Style: Ultra Rifled, button rifled, stress-relieved
Rifling Grooves: 6-groove (for .22–.338 calibers)
Contour: #4
Approx. Weight: ~3.35 lbs (finished #4 CM barrel) friscoguns.com
Configuration: Unchambered barrel blank, not threaded or chambered (gunsmith installation required)
Always confirm final dimensions and compatibility with your chosen action, stock, and intended cartridge with your gunsmith before ordering.
Why Choose the CONTOUR #4 3010CM4 Douglas Barrel Blank?
You should choose this barrel blank if you:
Want a high-quality .30-caliber barrel from a trusted name with decades of real-world performance behind it.
Are planning a custom hunting or precision build and need a #4 contour that balances accuracy and carry weight.
Prefer chrome moly steel for its strength, machinability, and suitability for traditional finishes like bluing.
Value the Douglas Double XX Ultra Rifled pedigree—button rifled, stress-relieved, and tightly toleranced for serious accuracy.
For gunsmiths, custom builders, and shooters who demand a rock-solid foundation for their next rifle, the CONTOUR #4 3010CM4 – Douglas .30 1-10 Twist CM #4 Contour Ultra Rifled Barrel is an excellent choice that blends tradition, precision, and practical performance.
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