Bushmaster® XM15-E2S® Stripped Lower Receiver – Bushmaster® Firearms

The foundation of any reliable AR-15 build starts with a component that meets exacting standards, especially when you are sourcing parts for use here in Tennessee. Whether you are a gunsmith in Knoxville assembling a precision rig for the range, a hunter in the Cumberland Plateau setting up a lightweight carbine for varmint control, or a collector in Nashville looking for a mil-spec starting point, the Bushmaster® XM15-E2S® Stripped Lower Receiver provides a solid, compliant base. This receiver is the legally serialized component of your firearm, and it is ready to be transferred through your preferred Tennessee FFL dealer before you begin your custom assembly.

What This Product Is and Who It Is For

This is a stripped lower receiver, meaning it is the housing for the fire control group, magazine well, and stock assembly, but it does not include internal parts, a trigger, or a buttstock. It is specifically the Bushmaster XM15-E2S model, which is a direct descendant of the military-spec M16 lower design, modified for semi-automatic use. This component is intended for individuals who want to build their own AR-15 from the ground up, selecting each part to match their specific needs and budget.

This receiver is suitable for several types of shooters. Target shooters will appreciate the consistent mil-spec dimensions that allow for precise trigger and upper receiver fitment. Home defenders can build a reliable carbine around this lower, knowing the forging is heat-treated and tested. Hunters who prefer to configure a lightweight or specialized upper receiver for game like wild hogs or coyotes will find this a cost-effective starting point. Collectors and enthusiasts who want a recognized brand name like Bushmaster for a period-correct or clone build will also value this component.

Key Specifications and Features

While this is a stripped receiver, the XM15-E2S designation implies a specific set of standard features and dimensions that you can expect. The following are the key specifications based on the product name and standard Bushmaster manufacturing practices.

• Caliber Marking: Multi-cal marked. This receiver is laser-engraved with “Multi” on the magazine well, allowing you to legally build it into any caliber that fits an AR-15 platform (such as .223 Remington, 5.56 NATO, .300 Blackout, 9mm, etc.) without needing to remark the receiver.
• Receiver Extension: Designed to accept a standard A2-style fixed stock buffer tube. The receiver is threaded for a standard carbine or rifle buffer tube, but the product name indicates compatibility with an A2 fixed stock setup.
• Material: Forged from 7075-T6 aluminum. This is the industry standard for strength and corrosion resistance, heat-treated to mil-spec T6 condition.
• Finish: Hardcoat anodized per MIL-A-8625 Type III Class 2. This finish is durable, non-reflective, and resistant to wear and chemicals.
• Weight: Approximately 0.7 to 0.9 pounds (stripped, without any internal parts or stock).
• Sights: None included. This is a stripped lower; sights are mounted on the upper receiver assembly.
• Capacity: Standard AR-15 magazine capacity. Accepts all standard AR-15/M16-pattern magazines (10-round, 20-round, 30-round, etc.).
• Trigger Pocket: Mil-spec dimensions. Accepts standard AR-15 trigger groups, including drop-in cassette triggers.
• Safety Selector: Standard mil-spec safety detent and spring pocket. Accepts standard or ambidextrous selectors.
• Bolt Catch: Standard mil-spec bolt catch pocket. Accepts standard or enhanced bolt catch/release assemblies.
• Magazine Release: Standard mil-spec magazine catch and button pocket.
• Rear Takedown Pin: Standard mil-spec rear takedown pin hole and detent pocket.
• Grip: Standard A2-style grip tang. Accepts any AR-15 grip designed for mil-spec lowers.
• Trigger Guard: Integral trigger guard that is standard mil-spec size. Accepts standard or enlarged trigger guards.
• Serial Number: Individually serialized on the left side of the magazine well, with manufacturer markings.

Feature Deep-Dive: Why This Specific Model Stands Out

The Bushmaster XM15-E2S stripped lower receiver is not a generic forging. It is manufactured by Bushmaster Firearms, a company with a long history of producing AR-15 components for both civilian and law enforcement markets in the United States. The forging itself is sourced from a reputable supplier and then machined to Bushmaster’s specifications, which are held to tight tolerances. This means that when you are assembling your rifle, the trigger pins will align correctly, the upper receiver will mate without excessive wobble, and the magazine well will feed reliably. This level of consistency is important for a part that is the foundation of your firearm.

The multi-cal marking is a practical feature for any builder. Instead of being limited to a single caliber engraving, this receiver is legally marked to accept any caliber that fits the AR-15 magazine well. This gives you the flexibility to change your upper receiver and barrel assembly without needing to purchase a new lower. For example, you can start with a .223 Wylde upper for target shooting, then later swap to a .300 Blackout upper for hunting, all using the same lower receiver. This reduces long-term cost and simplifies your inventory of serialized components.

The receiver is designed to accept an A2 fixed stock, which is a classic and stable platform. While many modern builds use collapsible stocks, the A2 stock offers a solid cheek weld and a longer length of pull that is preferred by many shooters for precision work or for those with longer arms. The receiver extension threads are cut to mil-spec depth and pitch, ensuring that any standard buffer tube—whether for a fixed A2 stock or a carbine adjustable stock—will thread on correctly. This gives you the option to use the receiver with a fixed stock or to install a different buffer tube later if you change your build plan.

The hardcoat anodized finish is more than just cosmetic. It is a protective layer that penetrates the aluminum surface, making it highly resistant to scratches, corrosion, and wear from repeated cleaning and handling. This is especially relevant for Tennessee shooters who may be using their rifles in humid conditions or during outdoor activities where exposure to moisture and dirt is common. The finish is also non-reflective, which is a practical consideration for hunters and tactical shooters who want to avoid glare.

Finally, the receiver is machined with a standard mil-spec trigger pocket that allows for a wide range of aftermarket triggers. Whether you prefer a single-stage trigger for fast shooting or a two-stage trigger for precision, you can install it without any modification. The pin holes are drilled to 0.154-inch diameter, which is the standard for mil-spec triggers, but they also accept many drop-in triggers designed for this size. This compatibility ensures that you are not locked into a single brand or type of fire control group, giving you full control over the feel and performance of your finished rifle.

Ideal Use Cases for This Receiver

This stripped lower receiver is a versatile component that can be configured for several specific roles. For target shooting and range use, you can build a dedicated precision rifle with a free-floated handguard, a match-grade barrel, and a two-stage trigger. The consistent mil-spec dimensions of the Bushmaster receiver will help ensure accuracy by providing a stable platform for the upper receiver and barrel assembly.

For home defense, this receiver can be built into a compact carbine with a 10.5-inch or 14.5-inch barrel, a collapsible stock (if you swap the buffer tube), and a red dot sight. The rugged construction of the 7075-T6 aluminum and hardcoat anodized finish means the rifle will stand up to the rigors of storage and occasional use without degradation. The multi-cal marking also allows you to choose a caliber like .300 Blackout for suppressed use if that is a consideration.

For hunting in Tennessee, this receiver is an excellent starting point for a varmint or hog rifle. You can build it with a lightweight profile barrel in .223 Remington or 6.5 Grendel, a low-mass bolt carrier group, and a fixed A2 stock for a stable shooting platform. The receiver’s compatibility with standard AR-15 magazines means you can use 10-round magazines for hunting in areas with capacity restrictions, or standard 20- or 30-round magazines for pest control.

For collectors and clone builders, this receiver is a faithful reproduction of the Bushmaster XM15-E2S design, which itself is based on the M16A2 pattern. If you are building a period-correct M16A2 clone or a Bushmaster-branded rifle from the 1990s or early 2000s, this lower receiver is the correct starting point. The markings and finish are consistent with original Bushmaster production.

Compatibility Notes

This stripped lower receiver is compatible with all standard AR-15 upper receivers, including those from brands like Aero Precision, BCM, Daniel Defense, Palmetto State Armory, and others. It accepts any mil-spec AR-15 trigger group, bolt catch, magazine release, safety selector, and grip. For ammunition, the receiver itself does not limit caliber choice; the caliber is determined by the barrel, bolt, and magazine you install. Common compatible calibers include .223 Remington, 5.56 NATO, .300 Blackout, 6.5 Grendel, 6mm ARC, 9mm (with appropriate magazine adapter), and .22 LR (with conversion kit).

For magazines, this receiver accepts all standard AR-15/M16-pattern magazines. This includes aluminum, steel, and polymer magazines from manufacturers such as Magpul, Lancer, Okay Industries, and Brownells. It also accepts drum magazines like the Magpul D-60 or SureFire MAG5-60. For holsters, this receiver is not a holstered component; holsters are designed for the complete firearm, typically the pistol or the lower receiver with a brace or stock attached. For accessories, the receiver has standard mil-spec pockets for all lower parts, so you can install ambidextrous controls, extended bolt releases, or match-grade triggers without modification.

Frequently Asked Questions

1. How does shipping to Tennessee work for this stripped lower receiver?

This product is a firearm receiver and must be shipped to a Federal Firearms License (FFL) dealer in Tennessee. We cannot ship this directly to a residential address. When you place your order, you must provide the name and address of your chosen Tennessee FFL dealer. We will verify their license and ship the receiver to them. You will then complete the ATF Form 4473 and a NICS background check at that dealer before taking possession. We ship via UPS