Aero Precision M4E1 Enhanced AR-15 Upper Receiver Assembly - Black

Manufactured by Aero Precision
SKU: APAR600201
Manufactured by Aero Precision
6 Reviews

In Stock

Standard orders will ship out within 1 business day if ordered by 3:30 pm CST, Monday-Friday. FFL orders will ship within 5 business days or less as long as we have the information for the transfer destination.

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The Aero Precision M4E1 upper is a one-piece design combining the handguard mounting platform with the upper receiver. Through superior engineering, they have condensed the parts needed to mount a free-floated handguard to a mere 8 screws. As the handguard mounting surface and upper receiver are of the same forging, not only is this a stronger system, it allowed for additional lightening cuts to save weight and promote more efficient cooling. Mounting is simple. Insert your barrel assembly into the M4E1 upper, tighten it using the provided barrel nut and wrench, then slide your rail on and tighten the rail screws. Within minutes you have a modular, free-floated rail.

NOTE: This upper receiver is not piston-kit compatible.

  • Machined from 7075-T6 forged aluminum, anodized black.
  • M4 feedramps
  • .250” takedown pin holes
  • Laser engraved T-marks
  • Preassembled with dust cover and forward assist.
  • Works with Aero Precision handguards but also fits most BAR system handguards.
  • Barrel nut and wrench are included.
  • Weight: 10.24oz
  • Barrel nut torque: 50 ft-lbs
  • Made in the U.S.A.
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BrandAero Precision
Feed RampsM4
FinishHardcoat Anodized
Forward AssistAssembled with Forward Assist
Manufacturer.Aero Precision
Port DoorAssembled with Port Cover
Receiver Material7075-T6 Aluminum
T MarksT-Marked
California Prop 65 warning

 WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information go to

Ratings & Reviews

6 reviews

  • 3 stars
  • 0 reviews
  • 2 stars
  • 0 reviews
  • 1 star
  • 0 reviews

My go to upper!


The price is right and the fit and finish are excellent. I only use Aero Precision for my builds. So far I've purchased two M4E1 uppers to use for my 300 Blackout SBRs and couldn't be happier.

Limited Handguard Options


but overall great productI bought this upper because I was building my first AR and it seemed like the easier option. However I didn't really notice how difficult it would be to find a handguard to fit the upper as a result. That being said this product makes swapping barrels easy as can be it saves you money and stress of finding additional parts such as the barrel nut and delta rings etc. I really wanted a magpul hand guard but you cannot use one with this upper. Your only option is a free float rail which does add some undesired weight to the front of the gun especially as you add accessories. However I am satisfied with the product it is a good price and my local gunsmith was impressed with the quality and unique design.

A Good Choice

by -

Very good quality. Kind of impressive really.So much better than the surplus parts I used to use. If it's worth doing.... BTW shipping was really quick. Primary Arms will be my source for new builds.

M4E1, the way to go


I bought one of these in FDE to mate with a Wilson Combat Lower, talk about a match made in gun heaven. Zero jiggle or wiggle.

No Moving Parts !!!!


I purchased the Aero Precision M4E1 upper with the 15" MLOK handguard for my 20" 6.5 Grendel build and I couldn't be happier. The barrel and handguard lock-up is great, no moving parts. This is a very solid lock -up and I would highly recommend it to anyone building an AR style platform rifle.

Only if you want the best


This is my 3rd enhanced upper from Aero Precision. All of my builds are sub MOA with low power (6x or less) optics at 100 yards. The entire point of this upper is to rid your build of any barrel flexure. On mil-spec builds when resting your handguard it puts stress on the barrel nut which in turn puts stress on the barrel causing a POI shift. This strengthens that weak spot significantly! The last one I bought the tolerance was so tight I had to freeze the barrel and use a hair dryer on hot on the upper to get it to fit, they've always been tight but this was machine fit tight! I wish all were this close fitting as it means no room for shifting. Great service as always from PA and AP!
<br>P.S. - bar type handguards are the best for structure support firing and maximizing air gap between your hand and a hot barrel during heavy engagement scenarios.