The AR-15 rifle has carved out a special place in the hearts of gun enthusiasts. Its versatility, customizability, and reliability make it a favorite among firearm owners. One key component that allows for this adaptability is the upper.
In this article, we’ll explore what an upper receiver is, and then dive into the best AR-15 complete uppers on the market today. Whether you’re a seasoned shooter or a newcomer to the AR-15 platform, this guide will help you make an informed choice when upgrading your rifle.
What’s the Upper Receiver?
Before we delve into the top AR-15 complete upper, let’s clarify what exactly the upper is. It’s the upper part of the rifle, housing critical components such as the barrel, bolt carrier group, and charging handle for the AR-15.
It plays a crucial role in determining the rifle’s accuracy, durability, and overall performance. A quality complete upper can significantly enhance your shooting experience.
Best AR-15 Complete Upper Receivers
1. Colt Enhanced Patrol Rifle (EPR) Upper
Barrel Length: The Colt EPR Upper features a 16-inch chrome-lined barrel. Chrome lining enhances durability and corrosion resistance, making it a reliable choice for extended use.
Full-Length Picatinny Rail: Equipped with a full-length Picatinny rail on top, this upper provides ample space for mounting optics, sights, and other accessories. It offers flexibility for customization, allowing you to tailor your rifle to your specific needs.
Robust Design: Colt is renowned for its build quality, and the EPR Upper lives up to this reputation. It’s designed for reliability, making it suitable for both recreational shooters and law enforcement professionals.
- Proven Reliability: Colt’s commitment to quality ensures that this upper can withstand rigorous use and perform consistently.
- Customization: The full-length Picatinny rail gives you the freedom to add optics, iron sights, and accessories as you see fit, providing a versatile shooting experience.
- Chrome-Lined Barrel: The chrome-lined barrel enhances longevity and corrosion resistance, reducing maintenance requirements.
- Price: While the Colt EPR Upper is known for its quality, it may be on the higher end of the price spectrum. However, many shooters consider it a worthwhile investment.
- Weight: Some users may find the Colt EPR Upper slightly heavier compared to other options due to its robust construction.
The Colt Enhanced Patrol Rifle (EPR) Upper is an excellent choice for those seeking a dependable upper receiver with a track record of performance. Its chrome-lined barrel, full-length Picatinny rail, and robust design make it well-suited for a variety of shooting applications, from range days to duty use.
While the price may be a consideration for budget-conscious buyers, the investment in Colt’s quality is often justified by its reliability and durability. If you value a versatile, dependable upper for your AR-15, the Colt EPR Upper is certainly worth considering.
It’s a solid foundation for building a rifle that meets your specific needs and preferences, whether you’re a seasoned shooter or a law enforcement professional.
2. Geissele Super Duty Upper
Barrel Length: The Geissele Super Duty Upper comes with a 14.5-inch barrel, making it a balanced choice for various shooting scenarios. It strikes a compromise between maneuverability and accuracy.
Free-Floating Handguard: Equipped with a free-floating handguard, this complete upper offers enhanced accuracy and the ability to attach accessories like grips, lights, and lasers without affecting barrel harmonics.
Geissele Quality: Geissele is renowned for its precision and craftsmanship. The Super Duty Upper lives up to this reputation with meticulous attention to detail in its design and construction.
- Precision: Geissele’s commitment to precision means that this complete upper is capable of exceptional accuracy, making it suitable for both competition shooting and tactical use.
- Versatility: The free-floating handguard provides a platform for customization, allowing you to tailor your rifle to your preferences with ease.
- Durability: Geissele’s reputation for quality extends to the durability of their products. The Super Duty Upper is built to withstand demanding conditions and prolonged use.
- Price: Geissele products often come with a premium price tag due to their high-quality materials and craftsmanship. It may not be the best choice for budget-conscious buyers.
- Availability: Given the popularity of Geissele products, there may be periods of high demand and limited availability, which could require some patience when trying to purchase one.
The Geissele Super Duty Upper is a top-tier choice for AR-15 enthusiasts and professionals who demand precision and quality. Its 14.5-inch barrel strikes a balance between maneuverability and accuracy, making it versatile for a wide range of shooting activities.
One of the standout features is the free-floating handguard, which allows for customization without sacrificing accuracy. Geissele’s reputation for precision and durability means that this upper receiver can handle demanding conditions and maintain consistent performance.
While the price may be a deterrent for those on a budget, the investment in Geissele’s craftsmanship and quality is often justified by the exceptional performance of their products. If you’re seeking an upper receiver that combines precision, versatility, and durability, the Geissele Super Duty Upper should be at the top of your list.
It’s an investment in a top-tier component that can significantly enhance your AR-15 rifle.
3. Daniel Defense Mk18 Upper Receiver
Barrel Length: The Daniel Defense Mk18 Upper is equipped with a compact 10.3-inch barrel. This shorter barrel length is ideal for close-quarters combat and maneuverability, making it a favorite among tactical shooters.
RIS II Handguard: The Mk18 features Daniel Defense’s RIS II (Rail Interface System) handguard, providing ample space for accessories, such as foregrips, lights, and lasers. Its robust design ensures durability and precision.
Cold Hammer Forged Barrel: Daniel Defense is known for its Cold Hammer Forged (CHF) barrels, which enhance barrel life and accuracy. The Mk18’s CHF barrel is no exception, ensuring reliable performance even under intensive use.
- Compact Design: The 10.3-inch barrel makes the Mk18 Upper highly maneuverable in tight spaces, making it a favored choice for military and law enforcement applications.
- RIS II Handguard: The RIS II handguard offers versatility for customization while maintaining the ruggedness required for demanding situations.
- CHF Barrel: Daniel Defense’s CHF barrels are celebrated for their accuracy and longevity, ensuring consistent performance over time.
- Restricted Range: The shorter barrel limits effective engagement ranges, making it less suitable for long-range shooting. It excels in close-quarters scenarios but may not be the best choice for precision shooting.
- Legal Restrictions: Depending on your location, there may be legal restrictions on the ownership and use of rifles with barrels shorter than 16 inches. Ensure you comply with local and federal laws before purchasing.
The Daniel Defense Mk18 Upper is designed for a specific purpose: close-quarters combat and tactical applications. Its compact 10.3-inch barrel and RIS II handguard make it a standout choice for military and law enforcement personnel who require maneuverability and versatility in tight situations.
The Cold Hammer Forged barrel adds durability and accuracy to the package, ensuring reliable performance even under demanding conditions. However, potential buyers should be aware of the limitations of a shorter barrel, particularly in terms of effective engagement range.
If your primary use case aligns with close-quarters scenarios, the Mk18 Upper is an outstanding option. Its quality construction, precision components, and reputation for reliability make it a top choice for those in need of a compact and capable complete upper receiver for their AR-15 platform.
4. Stag-15 Tactical Upper Left-Handed
Barrel Length: The Stag-15 Tactical Upper Left-Handed comes with a 16-inch barrel, offering a balance between maneuverability and accuracy. It’s chambered for 5.56 NATO ammunition, making it compatible with a wide range of ammunition options.
Left-Handed Configuration: This complete upper receiver is one of the many AR-15 components that’s designed explicitly for left-handed shooters. It features a left-handed bolt carrier group, ensuring improved ergonomics and reduced recoil for left-handed users.
M-LOK Handguard: The M-LOK handguard allows for easy attachment of accessories like lights, foregrips, and lasers. It offers flexibility while maintaining a sleek and lightweight profile.
- Left-Handed Friendly: For left-handed shooters, the Stag-15 Tactical Upper is a game-changer, providing a more comfortable shooting experience with reduced recoil and improved ergonomics.
- Versatile Barrel Length: The 16-inch barrel strikes a balance between maneuverability and accuracy, making it suitable for a variety of shooting scenarios, including home defense and target shooting.
- M-LOK Handguard: The M-LOK handguard offers versatility for accessory attachment, allowing you to customize your rifle to your liking.
- Limited Ambidextrous Use: While left-handed shooters benefit from the design, right-handed users may find it less versatile. This complete upper receiver is optimized for left-handed use.
- Price: The specialized left-handed configuration may come at a slightly higher price point compared to some right-handed alternatives. However, left-handed shooters often find it a worthwhile investment.
The Stag-15 Tactical Upper Left-Handed is a standout choice for left-handed shooters seeking an upper receiver tailored to their needs. Its left-handed bolt carrier group enhances the shooting experience by reducing recoil and improving ergonomics for southpaw users.
The 16-inch barrel provides a balance between maneuverability and accuracy, making it suitable for various shooting scenarios. The M-LOK handguard adds customization options without adding unnecessary weight or bulk.
While this upper receiver is purpose-built for left-handed shooters, it may not be as versatile for right-handed users. The price point may be slightly higher due to the specialized design, but left-handed shooters often find the investment justified for the improved experience.
If you’re a left-handed shooter looking to optimize your AR-15, the Stag-15 Tactical Upper is a solid choice.
5. Sons of Liberty Gunworks Patrol SL
Barrel Length: The Sons of Liberty Gunworks Patrol SL comes with a 16-inch barrel, offering a versatile balance between maneuverability and accuracy. It’s chambered for 5.56 NATO ammunition, making it compatible with a wide range of rounds.
M4 Feed Ramps: The inclusion of M4 feed ramps ensures reliable feeding and smoother cycling of the rifle, reducing the risk of malfunctions during firing.
M-LOK Handguard: The M-LOK handguard provides a lightweight and customizable platform for mounting accessories such as lights, grips, and optics. It allows for easy personalization without adding unnecessary weight.
- Versatility: The 16-inch barrel strikes an excellent balance between maneuverability and accuracy, making the Sons of Liberty Gunworks Patrol SL suitable for a wide range of shooting scenarios, from home defense to target shooting.
- Reliable Feeding: The M4 feed ramps contribute to reliable feeding, reducing the likelihood of malfunctions and ensuring consistent performance.
- Customization: The M-LOK handguard offers versatility for accessory attachment, allowing you to tailor your rifle to your specific needs and preferences.
- Price: The Sons of Liberty Gunworks Patrol SL may be on the higher end of the price spectrum, which could deter budget-conscious buyers. However, many users find the investment justified by its quality.
- Limited Specialization: While it’s a versatile upper receiver, it may not excel in specific niches like long-range precision shooting or ultra-compact configurations. It’s a well-rounded option for general-purpose use.
The Sons of Liberty Gunworks Patrol SL upper receiver offers a well-rounded and reliable choice for AR-15 enthusiasts. Its 16-inch barrel provides a versatile balance between maneuverability and accuracy, making it suitable for a wide range of applications, from home defense to recreational shooting.
The inclusion of M4 feed ramps enhances reliability, ensuring consistent and trouble-free cycling of the rifle. The M-LOK handguard allows for customization without adding unnecessary weight or bulk.
While the price may be a consideration for some, many users find the investment in Sons of Liberty Gunworks’ quality and craftsmanship well worth it. If you’re looking for a dependable and versatile upper receiver for your AR-15, the Patrol SL is a strong contender.
It’s a solid foundation for building a rifle that can adapt to various shooting scenarios with ease.
6. Foxtrot Mike FM-15 Upper
Barrel Length: The Foxtrot Mike FM-15 Upper is designed for pistol caliber carbines (PCCs) and comes with a 8.5-inch barrel, making it compact and suitable for close-quarters engagements.
Blowback Operation: This upper receiver utilizes a blowback operating system, which is common in PCCs. It simplifies the design and enhances reliability.
M-LOK Handguard: The M-LOK handguard provides a lightweight and customizable platform for mounting accessories such as lights, foregrips, and optics, allowing for easy personalization.
- Compact Design: The 8.5-inch barrel and PCC chambering make the Foxtrot Mike FM-15 Upper highly maneuverable and well-suited for home defense, personal protection, or competition shooting in confined spaces.
- Blowback Reliability: The blowback operating system is known for its simplicity and reliability, ensuring consistent cycling even with a variety of ammunition.
- Customization: The M-LOK handguard offers versatility for accessory attachment, allowing you to customize your PCC to your liking.
- Limited Effective Range: Due to the short barrel and pistol caliber chambering, the Foxtrot Mike FM-15 Upper is not optimized for long-range accuracy. It excels in close-quarters scenarios but may lack precision at extended distances.
- Specialized Use: It’s important to note that this upper receiver is designed specifically for pistol caliber carbines. It may not be compatible with standard AR-15 lower receivers chambered in rifle calibers.
The Foxtrot Mike FM-15 Upper is a specialized upper receiver designed for pistol caliber carbines (PCCs). Its compact 8.5-inch barrel and blowback operating system make it ideal for close-quarters engagements, such as home defense or competition shooting in confined spaces.
The blowback operating system is valued for its simplicity and reliability, ensuring consistent cycling with various ammunition types. The M-LOK handguard allows for customization, enabling users to add accessories to suit their preferences.
However, potential buyers should be aware of the limited effective range and the specialized nature of this upper receiver. It is not intended for long-range precision shooting. Additionally, compatibility may be restricted to lower receivers specifically designed for PCCs.
If you’re in the market for a compact and reliable upper receiver for your pistol caliber carbine, the Foxtrot Mike FM-15 Upper is a solid choice. It excels in its intended role, offering maneuverability and customization options for PCC enthusiasts.
7. Aero Precision 20-inch Rifle Upper
Barrel Length: The Aero Precision 20-inch Rifle Upper features an extended 20-inch barrel, optimized for long-range shooting and enhanced accuracy.
Rifle-Length Gas Systems: It utilizes a rifle-length system, which typically results in smoother recoil and more consistent cycling, especially with longer barrels.
Free-Floating Handguard: Equipped with a free-floating handguard, this upper receiver allows for precise barrel harmonics and the attachment of accessories without affecting accuracy.
- Long-Range Precision: The 20-inch barrel and rifle-length gas system make the Aero Precision upper receiver ideal for long-range shooting. It provides enhanced accuracy and a flatter trajectory, making it suitable for target shooting and precision applications.
- Smooth Recoil: The rifle-length gas system typically results in reduced recoil compared to shorter gas systems, contributing to improved control and follow-up shots.
- Customization: The free-floating handguard provides a platform for accessory attachment, allowing users to tailor their rifle to specific shooting preferences.
- Length and Weight: The extended barrel and rifle-length gas system add length and weight to the rifle, making it less maneuverable in close-quarters scenarios.
- Specialized Use: While the Aero Precision 20-inch Rifle Upper excels in long-range precision shooting, it may not be the best choice for applications that require a more compact and maneuverable rifle.
The Aero Precision 20-inch Rifle Upper is tailored for shooters who prioritize long-range precision and accuracy. Its extended 20-inch barrel and rifle-length gas system deliver exceptional performance in this regard, providing a flatter trajectory and reduced recoil for improved control.
While it excels in long-range shooting, users should be aware of its limitations in terms of length and weight, which may affect maneuverability in close-quarters scenarios.
This upper receiver is specialized for precision applications and may not be the ideal choice for those seeking a more compact and versatile AR-15 platform.
If your shooting interests lean towards precision target shooting, varmint hunting, or any application that demands exceptional accuracy at extended ranges, the Aero Precision 20-inch Rifle Upper is an excellent choice.
Its quality construction and design make it a reliable option for achieving consistent and precise shots downrange.
Buyers Guide for AR-15 Uppers
When choosing the right AR-15 upper receiver, there are several factors to consider to ensure it aligns with your needs and preferences. This buyer’s guide provides an overview of essential considerations:
The Upper Decks: Complete to Stripped
When shopping for an AR-15 upper receiver, you’ll encounter two main categories: complete and stripped upper receiver. Each type offers its own set of advantages and considerations.
Convenience: Complete upper receiver come fully assembled with all the necessary components, including the barrel, bolt carrier group, handguard, and sometimes even sights or optics. This means you can install the upper on your lower receiver and start shooting right away. It’s a hassle-free option for those who want a ready-to-use solution.
Quality Assurance: Since complete uppers are pre-assembled by reputable manufacturers, you can have confidence in the quality and compatibility of the components. This reduces the risk of compatibility issues or assembly errors.
Limited Customization: While convenient, the best upper receiver offer limited customization options. You’ll have to choose an upper that aligns closely with your desired specifications, as changing components later may require more effort and expense.
Customization: Stripped uppers are essentially a blank canvas. They come with the essential components, such as the upper itself and the barrel, but you’ll need to add the bolt carrier group, charging handle, handguard, and any other accessories. This allows for complete customization to create a rifle tailored to your preferences.
Flexibility: Stripped uppers provide the flexibility to choose each component individually, ensuring that every part of your AR-15 meets your specific requirements. It’s an excellent option for those who want to build a unique rifle.
Assembly Required: Building an AR-15 with a stripped upper requires more effort and potentially additional tools. You’ll need to assemble and align components correctly, which can be a rewarding experience for enthusiasts but may be intimidating for beginners.
Types of AR-15 Upper Receivers
When selecting an AR-15 upper, you’ll encounter various types, each with distinct characteristics. Understanding the differences between complete uppers, complete basic uppers, quasi-stripped uppers, and stripped uppers is essential for making an informed choice.
Complete Upper Receivers:
Fully Assembled: Complete upper receivers come fully assembled with all essential components, including the barrel, bolt carrier group, charging handle, and handguard. Some may even include sights or optics.
Ready to Use: These uppers are ready to be attached to a compatible lower receiver, making them a convenient choice for those who want a rifle without the hassle of component selection and assembly.
Limited Customization: While convenient, complete uppers offer limited customization options. You must choose an upper that aligns closely with your desired specifications, as changing components later can be more challenging and costly.
Complete Basic Upper Receivers:
Similar to Complete Uppers: Complete basic uppers are fully assembled like complete uppers but typically exclude sights or optics, allowing you to select your preferred aiming system.
Versatility: They offer a balance between convenience and customization, giving you the flexibility to choose your sights or optics to suit your shooting needs.
Quasi-Stripped Upper Receivers:
Partial Assembly: Quasi-stripped uppers are partially assembled. They typically include the barrel and upper receiver but may lack the bolt carrier group, charging handle, and handguard.
Customization Potential: These uppers provide more customization options than complete uppers while offering the convenience of a pre-installed barrel. You can select the remaining components to suit your preferences.
Stripped Upper Receivers:
Bare Essentials: Stripped upper receivers come with the bare essentials, typically just the upper receiver itself. They lack the barrel, bolt carrier group, charging handle, handguard, and sights.
Complete Customization: Stripped uppers offer the highest level of customization, allowing you to select every component individually. This is ideal for those who want to build a completely personalized AR-15 from scratch.
Assembly Required: Building an AR-15 with a stripped upper requires more effort and potentially additional tools. You’ll need to assemble and align components correctly, which can be a rewarding experience for enthusiasts but may be intimidating for beginners.
The length of the barrel of your AR-15 upper receiver plays a significant role in determining the rifle’s performance and suitability for specific applications. Here’s a breakdown of common various barrel lengths and their characteristics:
Short Barrels (Under 16 Inches):
Maneuverability: Short-barreled uppers, often found in lengths like 10.3 inches or 11.5 inches, excel in close-quarters and tactical scenarios. They are highly maneuverable in confined spaces, making them suitable for home defense and military or law enforcement use.
Velocity Sacrifice: Shorter barrels sacrifice some muzzle velocity, which can impact bullet performance and effective range. However, for their intended purposes, this drawback is often outweighed by the advantages of compactness.
Mid-Length Gas System Barrels (16 to 18 Inches):
Versatility: Mid length gas system Barrels in the 16 to 18-inch range offer a balanced compromise between maneuverability and accuracy. They (mid length gas system barrels) are versatile and suitable for a wide range of shooting applications, including target shooting, competition, and home defense.
Accuracy: Longer barrels in this range of mid length gas system tend to provide improved accuracy and velocity, making them ideal for precision shooting at medium ranges.
Long Barrels (20 Inches and Longer):
Long-Range Shooting: Long-barreled uppers, such as 20 inches or more, are designed for long-range precision shooting. They maximize velocity and accuracy, delivering consistent performance at extended distances.
Reduced Maneuverability: The trade-off for long-range capability is reduced maneuverability. These barrels are less suitable for close-quarters engagements or situations where rapid target transitions are required.
The handguard on your AR-15 upper receiver group is a critical component that affects the rifle’s aesthetics, functionality, and customization options. There are various types of handguards, each with its own advantages:
Accessory Compatibility: Quad-rail handguards feature Picatinny rails on all four sides, providing ample space for mounting accessories like lights, lasers, foregrips, and optics. They offer maximum customization options.
Weight: The metal construction of quad-rail handguards can add significant weight to your rifle, which may impact maneuverability.
Heat Transfer: Quad-rail handguards can become hot to the touch during extended firing sessions, necessitating the use of rail covers or gloves.
Lightweight: KeyMod handguards feature a lightweight design with keyhole-shaped attachment points. They reduce unnecessary bulk and weight, making them a favorite for those seeking a streamlined profile.
Accessory Attachment: KeyMod systems allow for the direct attachment of KeyMod-compatible accessories. While not as universal as Picatinny rails, they provide versatility for adding ccessories where needed.
Heat Dissipation: KeyMod handguards tend to offer better heat dissipation compared to quad-rail designs, resulting in less heat transfer to the shooter’s hand.
Sleek and Lightweight: M-LOK handguards feature a sleek and lightweight design with narrow attachment slots. They strike a balance between customization and weight savings.
Accessory Compatibility: M-LOK systems allow for the direct attachment of M-LOK-compatible accessories. While not as widespread as Picatinny rails, they offer a wide range of customization options.
Heat Dissipation: M-LOK handguards provide efficient heat dissipation, ensuring minimal heat transfer to the shooter’s hand during rapid firing.
Upgrading your AR-15 with a complete upper receiver can transform your shooting experience. Whether you prioritize precision, versatility, or specialized functionality, there’s a complete upper receiver on the market to suit your needs.
Remember to consider factors like the length of your barrel, handguard style, and whether you prefer a complete or stripped upper. With the right upper receiver, your AR-15 can reach its full potential.
What’s the difference between an upper receiver and a lower receiver in an AR-15?
The upper receiver houses the rifle’s barrel, bolt carrier group, and charging handle. It is responsible for the ejection of spent casings and the cycling of the action. The lower, on the other hand, contains the trigger group, magazine well, and controls. It is legally considered the firearm’s serialized component.
Can I change the upper receiver of my AR-15 to shoot different calibers?
Yes, you can change the upper receiver to shoot different calibers as long as the lower receiver is compatible with those calibers. This is a popular way to adapt the same lower receiver for various shooting needs.
Are there any legal restrictions when buying or building an AR-15 upper?
Laws regarding the purchase and assembly of AR-15 upper receivers vary by location. Be sure to research and comply with local, state, and federal regulations regarding firearms and firearm components. In some places, upper receivers may be subject to the same restrictions as complete firearms.
Can I use a complete upper from one manufacturer with a lower receiver from another?
In most cases, yes, you can mix and match upper and lower receivers from different manufacturers as long as they are both compatible with the same AR-15 platform and chambered for the same caliber. However, it’s essential to ensure proper fit and function before use.
How often should I clean and maintain my AR-15 upper receiver?
Regular cleaning and maintenance are essential for the reliable operation of your AR-15 upper receiver. The frequency depends on usage, but a general guideline is to clean and lubricate your rifle after every range session or every 500 rounds, whichever comes first.
Be sure to follow the manufacturer’s recommendations for cleaning and maintenance procedures.
What is headspace, and why is it important for AR-15 upper receivers?
Headspace refers to the precise clearance between the chamber of the stainless steel barrel and the bolt face, which ensures that the cartridge seats correctly and safely in the chamber. Proper headspace is critical for safety and accuracy.
When assembling or re-barreling an AR-15 upper receiver, it’s essential to check and, if necessary, adjust the headspace to ensure safe and reliable functioning. This process is typically done by a qualified gunsmith.