AR-15 Upper Parts are the backbone of rifle performance, ensuring reliability, smooth cycling, and accuracy across every shot. At Arm or Ally, we carry a wide selection of components that allow builders and shooters to fine-tune their platform for tactical use, competition, or range-day reliability. From AR-15 Charging Handles and AR-15 Bolt Carrier Groups to Gas Systems, Muzzle Devices, Sights, Scope Mounts, and Small Parts & Accessories, our inventory makes it easy to source high-quality gear in one place.

Top Brands Offering AR-15 Upper Parts

We partner with leading manufacturers to provide trusted AR-15 components. Radian Weapons and Breek Arms produce charging handles and muzzle devices known for ergonomic design and ambidextrous function. Toolcraft delivers mil-spec and enhanced bolt carrier groups that withstand rigorous use. Ballistic Advantage focuses on precision components that pair seamlessly with their barrels. Superlative Arms provides adjustable gas systems that allow shooters to fine-tune cycling, while Faxon Firearms balances innovation and durability in their muzzle devices. For optics support, Holosun is trusted for rugged mounts and sights, and Magpul remains a favorite for small parts and accessories that enhance usability.

Charging Handles

The charging handle is a simple but essential component, allowing you to chamber a round or clear a malfunction. Our AR-15 Charging Handles category includes ambidextrous designs that provide fast, smooth operation under pressure. Upgrades from Radian Weapons and Breek Arms offer improved leverage and ergonomics for competitive shooters and tactical users alike.

Bolt Carrier Groups

The AR-15 Bolt Carrier Group (BCG) is the heart of the rifle, driving reliability and accuracy. Toolcraft and Ballistic Advantage provide BCGs with nitride, phosphate, and nickel boron finishes to suit every shooter’s needs. Whether you’re looking for a mil-spec duty setup or enhanced coatings for smoother cycling, our BCG selection ensures consistent lockup and durability under high round counts.

Gas Systems

Gas systems are key to how your rifle cycles, affecting recoil impulse and reliability. Our AR-15 Gas Systems include adjustable blocks, tubes, and kits. Options from Superlative Arms let you fine-tune your rifle for suppressed fire, competition, or reduced wear, making your platform more adaptable to specific conditions.

Muzzle Devices

Managing recoil and muzzle rise is critical for control. Our AR-15 Muzzle Devices category includes flash hiders, brakes, and compensators engineered for performance. Faxon Firearms and Breek Arms are known for innovative designs that improve shot-to-shot control while maintaining durability.

Sights and Scope Mounts

Target acquisition depends on a secure and reliable sighting setup. Explore AR-15 Sights and Scope Mounts to pair with your optics or iron sights. Holosun’s optic-ready systems provide fast alignment and rugged dependability, while high-quality mounts ensure repeatable zero and consistent accuracy across platforms.

Small Parts & Accessories

Even the smallest parts can make a big difference. Our AR-15 Upper Small Parts & Accessories include dust covers, forward assists, sling mounts, and other essentials. Magpul and other trusted manufacturers offer enhancements that improve ergonomics and long-term durability. These finishing touches complete your upper receiver build and keep your rifle operating smoothly.

Why Choose AR-15 Upper Parts from Arm or Ally

Arm or Ally offers more than just parts—we provide a streamlined shopping experience with clear specs, competitive pricing, and fast shipping. Every product is chosen for its proven performance, ensuring your build will meet the demands of range use, competitive shooting, or tactical applications. Whether you’re assembling your first rifle or optimizing a professional-grade system, our inventory of AR-15 Upper Parts gives you the flexibility to build with confidence.

What parts are included in AR-15 upper assemblies?

Common upper assembly components include the barrel, bolt carrier group (BCG), charging handle, gas system, forward assist, ejection port cover, muzzle device, and the handguard or rail system that houses sights and mounts.

How do I choose the right bolt carrier group (BCG)?

Choose a BCG based on material and finish (nitride, phosphate, or stainless), compatibility with your caliber and gas system, and intended use (e.g., suppressed, duty, or competition). Match the BCG to the barrel extension and follow manufacturer torque/fit recommendations.

What gas system length should I use for my barrel?

Match gas system length to your barrel length and intended use: pistol-length and carbine systems favor shorter barrels and faster cycling, while mid-length and rifle systems typically provide smoother recoil and are better for longer barrels and accuracy-focused builds.

How do muzzle devices affect accuracy and recoil?

Muzzle devices influence felt recoil, muzzle rise, and gas behavior. Compensators and brakes reduce muzzle rise for faster follow-up shots, while flash hiders minimize visible signature. Pick a device that balances recoil control and your accuracy goals, and verify thread pattern compatibility.

Can I upgrade individual upper parts without replacing the whole upper?

Yes. Many shooters swap individual components—such as the BCG, gas block, muzzle device, or handguard—to tune performance without changing the entire upper. Always verify compatibility with your barrel, receiver, and gas system before installing upgrades.