Proof Research Pre-Fit Bolt Action Barrel – .308 Win, 20", 1:10" Twist, 5-Groove, Stainless Steel, 5/8"-24 Threaded – Drop-In for Sig Cross – 134498
Unlock the true potential of your Sig Cross rifle with the Proof Research Bolt Action Barrel Pre-Fit .308 Win 20" Stainless Steel, 1:10" Twist, 5-Groove, 5/8"-24 Threaded (134498, 843068134498). Designed as a precision drop-in barrel upgrade for the Sig Cross, this match-grade stainless barrel delivers exceptional accuracy, consistency, and durability for shooters who demand more from their lightweight precision hunting and long-range platforms.
Whether you’re building a do-it-all backcountry rifle, a rugged precision hunting rig, or a compact long-range setup, this Proof Research pre-fit .308 barrel gives your Sig Cross a serious performance edge.
Purpose-Built .308 Win Pre-Fit for Sig Cross
This barrel is specifically engineered as a drop-in replacement for the Sig Cross in .308 Winchester:
Chambered in .308 Win – one of the most proven and versatile rifle calibers
Pre-fit design – made to work with the Sig Cross action with minimal gunsmithing required
Ideal for hunters, precision shooters, and long-range enthusiasts wanting a high-end barrel upgrade
Instead of a full custom barrel job with complex fitting, you get a ready-to-install, premium barrel that’s built to tight tolerances for repeatable precision.
20" Stainless Steel Barrel – Balance of Length, Weight & Performance
This Proof Research pre-fit features a 20-inch stainless steel barrel, a popular length for modern .308 builds:
20" length offers an excellent balance of:
Velocity for long-range and ethical hunting shots
Manageable overall rifle length for field carry, vehicles, and tight terrain
Stainless steel construction helps resist corrosion and wear in harsh environments
Engineered as a performance barrel for both range work and hard-use hunting
If you want a .308 barrel that’s long enough to perform, but still compact and manageable for real-world use, this 20" configuration is right in the sweet spot.
1:10" Twist Rate – Optimized for Common .308 Bullet Weights
The barrel features a 1:10" twist rate (5-groove), ideal for stabilizing a wide range of .308 bullet weights:
Excellent for traditional 150–175 grain hunting and match bullets
Capable of stabilizing many heavier match bullets used in long-range shooting
Provides versatile performance for both:
Hunting loads (bonded, soft-point, monolithic)
Match and OTM-style precision bullets
This twist rate makes the barrel a great choice for shooters who experiment with different bullet weights and brands in their .308 Win rifles.
5-Groove Rifling – Smooth, Consistent, and Accurate
Proof Research uses 5-groove rifling in this barrel:
Reduces bullet deformation compared to traditional 6-groove rifling
Helps promote consistent engagement with the bullet jacket
Often associated with excellent accuracy and ease of cleaning
If you’re chasing tight groups and repeatable performance, this rifling profile supports the precision that Proof Research barrels are known for.
5/8"-24 Threaded Muzzle – Suppressor & Brake Ready
The muzzle is cut with a 5/8"-24 tpi thread, the industry-standard threading for many .30-caliber muzzle devices:
If you already own .30-caliber suppressors or brakes, this threading keeps your build modular and compatible.
Stainless Steel Match-Grade Construction
This Proof Research stainless steel barrel is purpose-built for precision:
Made from premium stainless steel selected for strength, consistency, and longevity
Match-grade tolerances for:
Chamber dimensions
Bore concentricity
Rifling uniformity
Designed to minimize variables that can degrade accuracy over time
The result is a barrel that maintains tight groups and predictable point of impact as you put more rounds through it.
True Drop-In Design for Sig Cross
One of the major advantages of this model is its drop-in compatibility for the Sig Cross rifle:
Designed around the Sig Cross barrel interface and system
Helps avoid the need for major gunsmithing work in many setups
Great option for shooters who:
Want to upgrade from the factory barrel
Want a second barrel for a specific role or load
Want match-grade performance without a full custom build
Always verify headspace and function with a qualified gunsmith or follow proper installation practices to ensure safe operation.
Upgrade Your Sig Cross for Hunting & Long-Range Precision
With this Proof Research .308 Win pre-fit barrel installed, your Sig Cross becomes an even more capable rifle:
Ideal for big game hunting where .308 Win is appropriate and legal
Perfect for backcountry and mountain hunting, thanks to the compact 20" length and lightweight Sig Cross platform
Great for long-range and precision rifle training, steel shooting, and practical accuracy work
If you use your Sig Cross as a do-it-all rifle, this barrel gives you the extra edge in consistency, precision, and confidence downrange.
Designed for Consistent, Repeatable Accuracy
Proof Research barrels are known for delivering excellent accuracy potential when properly installed and combined with quality ammo:
Built for cold-bore predictability and tight multi-shot groups
Support load development for reloaders who want to tune a .308 Win round to their rifle
Helps reduce flyers and inconsistent impacts caused by poor barrel quality
Whether you’re punching paper at 100 yards or ringing steel further out, this barrel is designed to track with your dope and data.
Perfect for Precision-Minded Sig Cross Owners
This pre-fit barrel is perfect for shooters who:
Own a Sig Cross in .308 Win and want to upgrade from the stock barrel
Want a dedicated precision or hunting barrel with a proven pedigree
Appreciate the quality and reputation of Proof Research components
Want to improve their rifle without sending it off for months of custom work
It’s a premium component built to match the expectations of serious precision shooters and discerning hunters.
Key Specs – Proof Research Pre-Fit Barrel .308 Win for Sig Cross (134498)
Manufacturer: Proof Research
Model: Bolt Action Barrel Pre-Fit
Caliber: .308 Winchester
Length: 20"
Twist Rate: 1:10"
Rifling: 5-groove
Material: Stainless steel
Muzzle Thread: 5/8"-24 tpi
Compatibility: Drop-in design for Sig Cross rifles
Part Number: 134498
UPC: 843068134498
Why Choose the Proof Research .308 Win 20" Stainless Pre-Fit for Sig Cross?
Direct pre-fit upgrade for Sig Cross rifles in .308 Win
20" barrel length balances velocity, accuracy, and handling
1:10" twist, 5-groove rifling optimized for a wide range of .308 bullet weights
5/8"-24 threaded muzzle ready for brakes, comps, and suppressors
Stainless steel match-grade construction for precision and longevity
Built by Proof Research, a trusted name in high-end precision barrels
If you’re ready to take your Sig Cross to the next level in terms of accuracy and performance, the Proof Research Bolt Action Barrel Pre-Fit .308 Win 20" 1:10" Twist (5 Groove), 5/8"-24 tpi Threaded, Stainless Steel, Drop-In Design for Sig Cross (134498, 843068134498) is a premium, purpose-built solution for demanding shooters.
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