Image unavailable
M4e1 5.56 Assembled Upper Receiver W/M-Lok Atlas S-One Handguard - M4e1 5.56 Assm Uppr 16'''' Mid-Len 12'''' M-Lok Atlas S-One Hg Blk
Our editorial team reviews specifications, product data, and field-use information to keep pages accurate.
$489.99
View on Brownells
You'll be taken to Brownells to complete your purchase.
Hunter's Outpost earns a commission from affiliate links at no extra cost to you.
SKU: 100054449
Overview
Built around Aero Precision’s M4E1 threaded assembled upper receiver, this complete upper is aimed at shooters who want a streamlined setup with a slim-profile handguard. The ATLAS S-ONE handguard is presented as a size- and weight-conscious option, making it a practical fit for lightweight builds and general field use. It includes a 16" 5.56 mid-length configuration with a low profile gas block and M-LOK mounting, giving the upper a clean, modern layout for accessory attachment. For hunters and outdoor shooters who value a compact, purpose-built upper without extra bulk, this package keeps the focus on simplicity and modularity.
Why Hunters Choose the Aero Precision
Complete Upper
Includes Aero Precision's ATLAS S-ONE
Designed Size
Size and weight in mind
Atlas Attachment
A stable mounting platform
M4e1 Threaded
Assembled upper receiver included
Choice 12-inch
15-inch M-LOK ATLAS S-ONE handguard
Key Features
- Complete upper receiver from Aero Precision
- Includes the ATLAS S-ONE handguard
- ATLAS attachment system provides a slim mounting platform
- M4E1 threaded assembled upper receiver
- Choice of 12-inch or 15-inch M-LOK ATLAS S-ONE handguard
- Available with 16-inch 5.56 Mid CMV barrel or 18-inch rifle barrel
Best Used For
- Hunters building a lightweight 5.56 upper for general field use and carry
- Users wanting a slim-profile handguard setup with M-LOK accessory mounting
- Shooters assembling a complete upper around Aero Precision's M4E1 platform
- Those needing a mid-length 16-inch upper for a balanced rifle build
Specifications
| Attachment System | ATLAS attachment system |
|---|---|
| Barrel Length | 16" or 18" |
| Barrel Profile | Mid CMV Barrel |
| Caliber | 5.56 |
| Color | Blk |
| Gas Block | Low Profile Gas Block |
| Gas Tube | Mid-Length or Rifle Length Gas Tube |
| Handguard | M-LOK ATLAS S-ONE Handguard |
| Handguard Length | 12" or 15" |
| Upper Receiver | M4E1 Threaded Assembled Upper Receiver |
Pros
- Complete upper includes Aero Precision's ATLAS S-ONE handguard.
- Designed with size and weight in mind for lightweight builds.
- ATLAS attachment system offers a slim profile with a stable mounting platform.
- M4E1 threaded assembled upper receiver included.
- Choice of 12-inch or 15-inch M-LOK ATLAS S-ONE handguard.
- Available with 16-inch 5.56 Mid CMV barrel and mid-length gas system.
Considerations & Trade-offs
- The ATLAS S-ONE handguard is built around a slim, lightweight profile, so it favors a trim setup over a more substantial feel in hand.
- This upper is offered with either a 12" or 15" M-LOK ATLAS S-ONE handguard, so the exact configuration matters when matching it to your intended use.
- The product description references both 16" 5.56 mid-length and 18" rifle-length barrel options, so buyers should verify the specific version before ordering.
- As a complete upper, it is a more specialized purchase than a standalone receiver, which may not suit builds that need different barrel or handguard specifications.
Suggested Comparisons
- AR-15 complete upper receiver assemblies
- Lightweight handguard-equipped uppers
- 16-inch 5.56 NATO upper receivers
- Mid-length gas system uppers
Suggested Accessories
- Optic mount
- Backup iron sights
- Weapon light
- Sling
Frequently Asked Questions
What comes included with this upper receiver assembly?
According to the product data, this is a complete upper that includes Aero Precision's M4E1 threaded assembled upper receiver and ATLAS S-ONE handguard. The listing also references a 16" 5.56 mid CMV barrel, with low profile gas block and mid-length gas tube depending on configuration.
What handguard options are listed for this upper?
The product data lists a choice of 12" or 15" M-LOK ATLAS S-ONE handguard. The title for this specific item indicates a 12" M-LOK ATLAS S-ONE handguard in black.
Is this upper set up for a lightweight build?
The source description says the ATLAS S-ONE line is designed with size and weight in mind and is intended as a fit for a lightweight build. No additional weight specifications are provided.
What caliber is this upper chambered for?
The product title and description identify it as a 5.56 upper. No other chambering information is provided in the source data.
Does the listing specify barrel length and gas system details?
Yes. The title specifies a 16" barrel and mid-length gas system. The short and long descriptions also mention a 16" 5.56 mid CMV barrel and a low profile gas block with a mid-length gas tube, depending on configuration.