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.

Features

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!