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M4e1 Upper Receivers Complete .300 Blackout - M4e1 300blk Assemble Upper Gov 16''''bbl Pistol-Length Thrd Blk
Our editorial team reviews specifications, product data, and field-use information to keep pages accurate.
$494.99
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SKU: 100054455
Overview
Built around Aero Precision’s M4E1 threaded assembled upper receiver, this complete upper is aimed at hunters and shooters putting together a lightweight .300 Blackout setup. The ATLAS S-ONE handguard is designed to keep the profile slim while supporting a dependable mounting platform, making it a practical choice for a streamlined build. With .300 Blackout CMV barrel options and M-LOK configuration, it suits compact rifle setups where reduced bulk and straightforward accessory mounting matter. The trade-off is that this is a purpose-built upper assembly, so it should be matched to the rest of the rifle with the intended use and barrel length in mind.
Why Hunters Choose the Aero Precision
Complete Upper
From Aero Precision for .300
Atlas S-one
Handguard emphasizes a slim profile
Proprietary Atlas
Attachment system provides a durable
M4e1 Threaded
Assembled upper receiver included
Multiple Handguard
Barrel length options are listed
Key Features
- Complete upper receiver from Aero Precision for .300 Blackout builds.
- Includes the M4E1 threaded assembled upper receiver.
- Features the ATLAS S-ONE handguard with a slim profile.
- ATLAS attachment system is described as durable and dependable.
- Offered with M-LOK ATLAS S-ONE handguard and CMV barrel options.
- Designed with size and weight in mind for lightweight builds.
Best Used For
- Hunters building a lightweight .300 Blackout upper for compact, streamlined setups.
- Shooters wanting an Aero Precision complete upper with ATLAS S-ONE handguard.
- Users planning a .300 Blackout build with M-LOK accessory mounting options.
- Hunters who prefer a slim-profile upper for easier handling in the field.
Pros
- Complete upper from Aero Precision for .300 Blackout builds.
- ATLAS S-ONE handguard emphasizes a slim profile and lightweight design.
- Proprietary ATLAS attachment system provides a durable mounting platform.
- M4E1 threaded assembled upper receiver included.
- Multiple handguard and barrel length options are listed in the product data.
Considerations & Trade-offs
- The ATLAS S-ONE handguard is built around a slim, lightweight profile, so it favors a streamlined setup over a bulkier front end.
- This is a complete upper, not a full rifle, so it still requires a compatible lower and any other components needed to finish the build.
- The listing presents multiple handguard/barrel length combinations, so buyers should confirm the exact configuration before ordering.
- The .300 Blackout chambering is specific to this upper, which makes it a focused choice rather than a general-purpose option for other calibers.
Suggested Comparisons
- AR-15 upper receivers
- .300 Blackout complete uppers
- M-LOK handguard upper assemblies
- lightweight rifle build components
Suggested Accessories
- M-LOK rail accessories
- Weapon light
- Sling
- Optic mount
Frequently Asked Questions
What is included in this complete upper receiver assembly?
The product description says this complete upper includes an Aero Precision M4E1 threaded assembled upper receiver and an ATLAS S-ONE handguard. The listing also shows .300 Blackout CMV barrel options paired with different handguard lengths.
What caliber is this upper built for?
This upper is listed as a .300 Blackout complete upper.
What handguard system does it use?
It uses Aero Precision's ATLAS S-ONE handguard with an M-LOK interface and the proprietary ATLAS attachment system.
Are there different configuration options available?
Yes. The description shows multiple pairings, including a 7-inch M-LOK ATLAS S-ONE handguard with a 7-inch .300 Blackout CMV barrel, and a 9-inch M-LOK ATLAS S-ONE handguard with a 10-inch .300 Blackout CMV barrel. The listing text is truncated after that, so other options are not fully visible here.
Is this described as a lightweight setup?
Yes. The S-ONE handguard line is described as being designed with size and weight in mind for a lightweight build.