The Gorilla Machining AR-15 M4A4 Stripped Upper Receiver – Raw is precision machined from a 7075-T6 aluminum forging supplied by Anchor Harvey, one of the established names in aluminum forging.
Anchor Harvey is recognized for its aluminum forging capabilities and its distinctive “Split A” forge mark, which identifies the origin of the raw forging used to manufacture the receiver.
This stripped upper receiver features M4 feed ramps, a Mil-Std 1913 Picatinny rail, and dimensions machined to Mil-Spec standards for broad compatibility with AR-15 components.
Because this receiver is supplied in a raw, unfinished aluminum finish, it is an excellent option for builders, manufacturers, and custom projects where the final coating or finish will be selected separately.
Pair it with one of our compatible Gorilla Machining AR-15 lower receivers for a quality foundation for your next build.
Anchor Harvey 7075-T6 Aluminum Forging
Distinctive Anchor Harvey “Split A” Forge Mark
Precision machined to Mil-Spec dimensions
Raw / Unfinished Aluminum
M4A4-style flat-top upper receiver
Integrated Mil-Std 1913 Picatinny Rail
M4 Feed Ramps
Machined for barrels utilizing an M4 barrel extension
Compatible with a wide range of AR-15 components and calibers
Ideal for custom finishes, coatings, and personalized builds
This Gorilla Machining stripped upper starts with a 7075-T6 aluminum forging from Anchor Harvey.
Anchor Harvey is an American aluminum forging company with extensive experience producing precision forged components for demanding applications. Its recognizable Split A forge mark identifies Anchor Harvey as the company responsible for producing the original aluminum forging.
It is important to understand the difference between the forge manufacturer and the manufacturer responsible for machining the finished component. The Anchor Harvey mark identifies the source of the forging; the forging is subsequently precision machined into the finished AR-15 upper receiver.
For customers who pay attention to AR-15 forge markings, the Anchor Harvey Split A provides an easy way to identify the forging source.
An AR-15 stripped upper receiver serves as the main housing for several major components of the upper assembly, including the barrel assembly, bolt carrier group, charging handle, forward assist, and ejection-port components.
A stripped upper receiver does not include these internal or attached components, allowing the builder to select the individual parts that best fit the intended configuration.
Starting with a stripped upper receiver gives you greater control over your AR-15 configuration. Instead of purchasing a preassembled upper with predetermined components, you can select the barrel, handguard, bolt carrier group, charging handle, muzzle device, and other compatible parts individually.
This makes a stripped upper an excellent foundation for:
Custom AR-15 builds
Replacement upper receivers
Lightweight configurations
Competition-oriented builds
Hunting and sporting configurations
Custom Cerakote or anodized finishes
Manufacturer and gunsmith projects
7075-T6 aluminum is widely used for AR-15 receiver forgings because it provides an excellent combination of strength, durability, and relatively low weight.
The forging process shapes the aluminum under substantial pressure before the receiver undergoes final precision machining. This Gorilla Machining upper begins as an Anchor Harvey 7075-T6 forging before being machined into its final M4A4-style configuration.
Unlike a finished black anodized receiver, this upper is supplied raw and unfinished.
The exposed aluminum makes it particularly useful for customers who intend to apply their own final finish, including compatible anodizing or coating processes.
Please note that because this product is raw aluminum, the appearance may include normal machining marks, color variations, or other cosmetic characteristics associated with an unfinished machined component.
This stripped upper receiver is designed around standard AR-15/M4-pattern dimensions and is compatible with a wide variety of properly specified AR-15 components.
The receiver features M4 feed ramps and is machined for use with barrels utilizing an M4 barrel extension. Its integrated Mil-Std 1913 top rail provides a standard mounting interface for compatible optics, sights, and accessories.
Platform: AR-15 / M4Receiver Type: Stripped Upper ReceiverStyle: M4A4 Flat TopMaterial: 7075-T6 AluminumForging Manufacturer: Anchor HarveyForge Mark: Anchor Harvey “Split A”Finish: Raw / Unfinished AluminumTop Rail: Mil-Std 1913 PicatinnyFeed Ramps: M4Barrel Extension Compatibility: M4-styleConfiguration: StrippedBrand: Gorilla Machining
The Gorilla Machining AR-15 M4A4 Stripped Upper Receiver – Raw with Anchor Harvey Forging provides a quality starting point for customers who want control over their AR-15 configuration and final finish.
With its 7075-T6 forged aluminum construction, Anchor Harvey Split A forge mark, M4 feed ramps, Mil-Std 1913 rail, and raw finish, this receiver provides a versatile foundation for custom AR-15 projects.
