M4E1 Threaded Assembled Upper Receiver - Anodized Black

Aero Precision

MSRP: $134.99
Our Price: $124.99
(You save $10.00 )
(3 reviews) Write a Review
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The M4E1 Threaded Upper Receiver features a new angular machined design that helps it stand apart from standard mil-spec upper receivers. This upper receiver features the same enhanced body profile as our M4E1 Enhanced Upper Receiver but is threaded to accept a standard AR15 barrel nut. It is forged from 7075-T6 Aluminum, precision machined to work with all mil-spec AR15 parts and includes the port door and forward assist pre-installed for your convenience.

Bexar Arms offers receiver face squaring for an additional $10 charge. More information on receiver squaring can be found below.



  • New enhanced forging that gives the upper receiver a "billet look"
  • M4 Feedramps
  • .250 takedown pin holes
  • Laser engraved T-marks
  • Includes threaded forward assist roll pin
  • Includes port door and forward assist
  • 8.65oz
  • 100% Made in USA


Squaring the Receiver Face

At Bexar Arms, we offer you the option to have the face of your receiver squared. Squaring the face of the receiver is an essential step in accurizing your AR pattern rifle, and ensures your barrel seats firmly and completely with the receiver face and is perfectly inline with the BCG raceway in the upper. This allows for a more consistent bolt engagement which evenly distributes force among all of your bolt lugs instead of only a few. This consistent lockup and complete barrel seating can help increase your AR's maximum accuracy potential as well as extend the life of your bolt. While squaring your receiver face is 100% unnecessary for your rifle to function, if you're looking to squeeze the absolute most performance out of your AR pattern rifle, we highly recommend it!

To learn more about receiver squaring, click here to see our blog post on the topic!

3 Reviews Hide Reviews Show Reviews

  • 5
    The right part to match M4E1 lower

    Posted by Barry Beardslee on Dec 15th 2020

    I bought 2 of these for 2 builds. These match up very nicely with M4E1 lowers. The finish on both are flawless and a perfect match to the lowers. And with the threaded forward assist pins there is zero change of marring the finish driving in a roll pin. These are the only uppers I will use.

  • 5
    Excellent Quality and Service

    Posted by Daniel on Jun 23rd 2020

    Received in great condition with an excellent squaring job.

  • 5
    Love it

    Posted by Sam Ford on Jan 17th 2020

    Great machine work, and fast shipping. My barrel never looked more at home.