Building a heavy barrel AR-15 for precision long-range shooting

The quest for precision long-range shooting often leads enthusiasts to consider building a custom rifle. Among the available platforms, the AR-15 is a popular choice due to its modularity, versatility, and wide range of aftermarket components. This article will guide you through building a heavy barrel AR-15 specifically designed for precision long-range shooting.

A heavy barrel AR-15 offers several advantages for long-range accuracy. The additional weight helps mitigate recoil and provides better stability during shooting, while the thicker profile can enhance heat dissipation during extended shooting sessions. This build guide will provide clear specifications, trade-offs, and realistic options for each subsystem involved in constructing your precision rifle.

Use-case overview

Before diving into the specifics of the build, it's essential to define the intended use case. This build is tailored for precision long-range shooting, which typically means engaging targets at distances greater than 300 yards. Such applications may include competitive shooting in events like Precision Rifle Series (PRS), hunting at extended ranges, or simply honing marksmanship skills on the range.

Key considerations for a long-range AR-15 build:

1. Barrel length and profile: A longer barrel generally improves velocity and accuracy but can add weight and affect maneuverability.

2. Optics selection: Quality optics are critical for identifying and hitting distant targets accurately.

3. Trigger system: A crisp trigger can significantly enhance accuracy by reducing pull weight and travel.

4. Stability: The stock and chassis choice must provide support while maintaining comfort during extended periods of use.

5. Ammunition: Choosing the right caliber and load is vital for achieving desired performance metrics.

Major subsystems

Barrel/gas system

The heart of any precision rifle is its barrel. For a heavy barrel AR-15, you’ll want to focus on options that balance weight with accuracy.

Barrel options

1. Ballistic Advantage Heavy Profile Barrel

   • Length: 20 inches

   • Twist Rate: 1:8

   • Material: Stainless Steel

   • Expected Accuracy: 0.75 MOA with match ammunition

2. Shilen Select Match Barrel

   • Length: 24 inches

   • Twist Rate: 1:8

   • Material: Chrome-moly steel

   • Expected Accuracy: 0.5 MOA with handloads

3. Faxon Firearms Heavy Fluted Barrel

   • Length: 18 inches

   • Twist Rate: 1:8

   • Material: 4150 CrMoV steel

   • Expected Accuracy: 0.75 MOA with quality factory ammo

Gas system considerations

For a long-range AR-15, you will typically want a rifle-length gas system to ensure smooth cycling and reduced recoil impulse, which aids in follow-up shots.

• Adjustable gas block: An adjustable gas block allows fine-tuning of the gas flow to accommodate various ammunition types and suppressor usage, improving reliability and reducing recoil.

Receiver and bolt

The receiver serves as the backbone of your rifle, housing critical components. While most standard AR-15 receivers will suffice, consider a few factors for enhanced performance.

Receiver options

1. Aero Precision M4E1 Upper Receiver

   • Weight: 7.2 ounces

Bolt carrier group (BCG)

A quality BCG is crucial for reliability and accuracy. Look for options that are properly staked and made from durable materials.

• Toolcraft M16 BCG

  • Material: 9310 steel

  • Finish: Nitride

  • Features: Enhanced reliability and durability.

Optics

Selecting the right optics is essential for long-range precision shooting. A good scope will allow you to accurately engage targets at extended distances.

Scope options

1. Vortex Viper PST Gen II 5-25x50

   • Reticle: EBR-2C MOA

   • Field of View: 24.5 ft at 100 yards (5x)

   • Weight: 30 oz

   • Price Range: $900-$1,200

2. Leupold Mark 5HD 5-25x56

• Reticle: TMR or LR Duplex

• Field of View: 24 ft at 100 yards (5x)

• Weight: 27 oz

• Price Range: $1,700-$2,200

Trigger

A high-quality trigger can drastically improve your shooting experience by providing a clean break and reducing pull weight.

Trigger options

1. Geissele Automatics Super Dynamic 3 Gun (SD3G)

   • Pull Weight: Approximately 3 lbs

   • Features: Short reset, flat bow design for better finger placement.

2. Timney Triggers Calvin Elite

   • Pull Weight: Adjustable between 1.5 lbs to 4 lbs

   • Features: Crisp break with minimal overtravel.

3. CMC Triggers Drop-In Curved Trigger

   • Pull Weight: Available in various weights (3.5 lbs, 4 lbs)

   • Features: Easy installation, reliable performance.

Stock/chassis

The stock or chassis influences comfort and stability during shooting sessions. Choose options that provide good ergonomics while accommodating your shooting style.

Stock options

1. Magpul PRS Gen3 Precision Adjustable Stock

   • Features: Fully adjustable length of pull and cheek weld.

   • Weight: Approximately 1 lb, 12 oz.

2. LUTH-AR MBA-1 Modular Buttstock Assembly

   • Features: Adjustable length of pull with an ergonomic design.

   • Weight: Approximately 1 lb, 8 oz.

3. Bergara B14 HMR Chassis

   • Features: Integrated chassis system designed for long-range accuracy.

   • Weight: Approximately 3 lbs.

Support gear

In addition to the rifle itself, consider additional gear that enhances your long-range shooting experience.

Gear options

1. Bipod

   • A quality bipod provides stability when shooting from prone positions. Options include the Harris S-BRM Bipod or the Atlas BT10 Bipod.

2. Sling

   • A two-point sling can help stabilize the rifle during offhand shooting or when transitioning between positions. Consider the Magpul MS3 Sling for versatility.

3. Data Book

   • Keeping a data book allows you to record your dope (data on previous engagements), wind conditions, and other critical information for future reference.

Spec Check

Common mistakes

1. Focusing too much on aesthetics instead of functionality when selecting components.

2. Neglecting to properly torque screws and fasteners during assembly.

3. Overlooking the importance of a quality optic in favor of budget options.

4. Not considering how barrel length affects maneuverability vs. accuracy.

5. Forgetting to take accurate measurements and adjustments when zeroing the rifle.

Field note

Imagine you are preparing for a local precision rifle match where you will need to engage targets at varying distances up to 800 yards. You’ve built your heavy barrel AR-15 based on this guide, equipping it with a Ballistic Advantage barrel, Vortex Viper PST scope, and Geissele trigger. On match day, you set up your rifle on a stable bipod and use your dope chart from previous practice sessions to make quick adjustments based on wind conditions. Your setup allows you to confidently engage targets while keeping track of your performance throughout the day.

Conclusion

Building a heavy barrel AR-15 tailored for precision long-range shooting involves careful consideration of each component's role in achieving accuracy and reliability. By selecting high-quality parts across the barrel, receiver, optics, trigger, stock, and support gear, you can create a rifle that excels in performance while catering to your specific needs as a shooter.

Ultimately, this guide provides you with a framework to make informed decisions throughout your build process while emphasizing the importance of balance between weight, stability, and overall functionality in achieving long-range success with your AR-15 platform. Whether you're competing in matches or honing your skills on the range, this heavy barrel configuration will serve you well in achieving precision results at extended distances.