Aero Precision Upper Review: M4E1 16” 5.56 Mid-Length

This is the complete upper receiver I recommend to my friends who want the best bang for their buck.

It’s also the upper that is taking the place of my previous home-defense setup.

Aero Precision M4E1 5.56 Mid-Length Complete Upper
Aero Precision M4E1 5.56 Mid-Length Complete Upper

I’ll walk through everything from fit & feel, to shootability, accuracy, upgrade potential, how it performs in competition, and more.  

Get ready for tons of pics and maybe a video or two of it in action.

About the Aero M4E1 Upper

The specific upper Aero Precision sent me to test is the M4E1 16” 5.56 Mid-Length ($429) with a 12” M-Lok handrail.  It’s their most popular and for good reason…

Aero M4E1 Midlength Upper

Prices accurate at time of writing

It combines everything I talk about in my AR-15 Buyer’s Guide:

  • 16” barrel so it satisfies all laws regarding length
  • Mid-length gas system for a softer shooting gun
  • Free-floating 12” handrail so you can get better accuracy + a longer grip
  • M-Lok attachment system so you can easily add lights, etc.

Who Is It For?

I’d say the M4E1 is a pretty general use upper.  But especially useful if…

  1. You’re looking for another AR-15 upper that has all the new stuff (mid-length gas, free-floating handrail, and M-Lok)
  2. You’re building a new AR but don’t want to mess with installing the barrel and gas system.  They require tools and I’ve messed up my fair share.  Sometimes you just want a reputable company to build it.
  3. You want the best value upper (or full rifles here).

Fit & Feel

Let’s go through all the parts starting with the “engine” of the gun…the BCG.  

Aero Precision BCG
Aero Precision BCG

It’s MPI/HPT tested and properly staked…like all my other mil-spec BCG’s that just plain work.  Also correct weight for a full-auto (FA) BCG.

BCG Weight
BCG Weight

I got the ambidextrous charging handle which is super beefy and useful if you want to easily brass check (using your right hand on the right side of the handle).  

Ambidextrous Charging Handle
Ambidextrous Charging Handle

Otherwise, it’s probably not worth the extra $40 from the regular one.  But still a good deal compared to my favorite Bravo Company one.

Note that the upper doesn’t come with the BCG nor charging handle (sadly this is the norm for uppers now), but Aero’s versions are priced well.

I also got the flip-up sights ($125) which are metal and again…super beefy.  I really like having them on a home defense gun just in case my optic fails.  It’s a little expensive so if you are looking for cheaper backup sights…look at Magpul polymer ones ($80).

Flip Up Sights Weight
Flip Up Sights Weight

Which hopefully it doesn’t since I’m using an Aimpoint.  Check out my recs for the best AR-15 optics.

The rail is machined nicely and has my favorite M-Lok attachment system pioneered by Magpul.  No more quad-rails since that adds unnecessary weight.

Aero Side
Aero Side

One thing to watch out for is that the handguard is kinda…fat.  At 2” it’s a little more thick than other handguards.  I got used to it shortly and it didn’t affect my shooting times.

*Update* Aero’s Gen 2 Handguards are in which are much thinner in profile!

Aero Handguard Width
Aero Handguard Width

The gas block is properly lined up and attached by two set screws.  I don’t think it’s going anywhere.

Aero Gas Block
Aero Gas Block

The M4E1 comes with a standard flash hider but since I’m going the featureless route, I swapped it out with my favorite J-Comp Compensator (OP) which kicked butt in this muzzle device shootout.

*Update 2017* The J-Comp is not ok for featureless builds so now I’m rocking a VG6 Gamma ($75) muzzle device.

Aero Flash Hider
Aero Flash Hider
Aero Flash & J-Comp
Aero Flash & J-Comp

The biggest difference in the Aero “enhanced” upper receiver is that the connection points with the handguard are forged into the receiver.  You can see the difference here:

Aero Enhanced M4E1 Upper Receiver
Aero Enhanced M4E1 Upper Receiver

Versus a regular upper.

Aero Assembled Upper Receiver
Aero Assembled Upper Receiver

That gives it extra strength and also a continuous top rail.

Aero T-Marks
Aero T-Marks
Aero Enhanced Upper Side
Aero Enhanced Upper Side

The upper receiver is also styled more than others that are rounded.  Personally, I like the more aggressive lines.

Aero Upper Receiver Syling
Aero Upper Receiver Syling

The complete weight of the upper with BCG and flip up sights is 4 lbs 7.4 oz which makes it a little heavier than other 16” uppers.  I think this is mainly due to the handguard.  However, the balance of it is fine.

Aero Complete Upper Weight
Aero Complete Upper Weight

So…enough about how it looks.

How Does it Shoot?

After some quick cleaning to get rid of any preservatives or oil, I lubed it up and went to the range.

Cleaning Up the Aero
Cleaning Up the Aero

I zeroed in the flip up sights and shot 100 rounds at 100 yard steel.  No malfunctions of any kind.

I’m glad I didn’t have to say to myself…“oh, it just needs a couple hundred rounds to break it in.”

Then came the fun part of taking me out of the equation and shooting groups.

Accuracy

Aero M4E1 Shooting Groups
Aero M4E1 Shooting Groups

The results of a 10-round slow string with no cooldown in-between shots with the PMC and my favorite single-stage trigger.

Aero PMC Results
Aero PMC Results

Yes, I messed up one round but it’s roughly 1” (1 MOA).  Which is pretty great for plinking ammo at 100 yards.  

By comparison military XM193 rounds are around 2-3” at 100 yards.

If you look you’ll see the sad face next to Wolf.  I was walking back from the targets and somehow lost the Wolf Shoot-n-C.  I would estimate it was around 2 MOA.  

Unfortunately I didn’t get the chance to chrono but I imagine it to be normal velocities.

Accuracy conclusion…I tried to make it the best possible case with a lead sled, a sweet optic, and a crisp trigger.  The rifle holds up so now it’s really down to the shooter.

Recoil/Shootability

I put on my red dot since I wanted to see how fast I could transition between targets at my next competition.

Aero Upper with Aimpoint
Aero Upper with Aimpoint

Recoil and shootability are on par with all the other AR-15’s I’ve shot that aren’t using adjustable gas-blocks.  Which is still…very little due to the small .223 round plus the compensator.

Competition

I normally run my lightweight upper but wanted to put the Aero M4E1 upper through the ringer.  

Competitions and me just have a really good track record of breaking down and exposing flaws in guns.

My main problem was choosing to go with the red dot and not getting enough time shooting at long range targets to memorize the drop.

I regularly place in the 50 percentile mark at my local matches and this time was no different.  I re-lubed at the beginning of the match and had no problems.

The Aero feeling at home with other AR-15’s.

Aero at Competition
Aero at Competition

Now we’re in the home stretch

Specifications

From the Aero site:

Upper

  • Forged from 7075 T6 aluminum
  • M4 feedramps
  • Matte black hard coat anodized Mil 8625 Type 3 Class 2
  • Laser engraved T-marks (Anodized only)

Handguard

  • 1pc free float design
  • Built in anti-rotation tabs
  • Scalloped rails
  • Continuous top rail

Barrel

  • 5.56 Nato 16″ Midlength, 1/7 twist, 4150 CrMoV, QPQ, gas port drilled
  • .750 gas block journal
  • Midlength gas system, .0785 gas port
  • M4 Feed Ramp Extension
  • HP and MPI tested
  • Standard A2 flash hider

By the Numbers

Reliability: 5/5

No failures of any kind in the ~700 rounds I’ve fired.  But remember to keep it nice and lubed.

Accuracy: 5/5

It’ll do its job with regular plinking ammo.  If you start to reload or use match ammo, you can likely make it a sub-MOA gun if you do your part.

Ergonomics: 4/5

My personal preference is for a thinner handguard, but I got used to it pretty quickly and don’t think it cost me any time during competition.  *Update* New Gen 2 handguards are much thinner and would bump this to a 5.

Looks: 5/5

Pretty sweet and the details on the receiver make it stand out.

Customization: 5/5

It’s an AR-15 with M-Lok so the sky’s the limit.  Check out my list of the best AR-15 upgrades if you need help.

Bang for the Buck: 5/5

Aero has proven themselves to me as the best bang for the buck in stripped receivers (I have build 6+ uppers on Aero), complete uppers, and full rifles.

Overall Rating: 5/5

Conclusion

If you’re thinking of getting an AR-15 upper, you can’t go wrong with the Aero Precision M4E1 16″ Mid-Length ($429).  They also have other variants (thinner profile pencil barrel for weight reduction or .223 Wylde chamber for increased accuracy.

Or…you can check out other options in our Best AR-15 Uppers for the Money article.

My best recommendation is that the M4E1 is now outfitted with a light and mount and ready to rock and roll at home if it’s ever needed.

Aero M4E1 Midlength Upper

Prices accurate at time of writing

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15 Comments on "Aero Precision Upper Review: M4E1 16” 5.56 Mid-Length"

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Ricardo
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JUST bought an Aero (16″ Wylde FDE Mlok) yesterday, can’t wait for it to arrive.

Zak
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I’m trying to decide between Aero Precision and Core 15. Have you had a chance to review any Core 15 rifles? And further how do Core 15 stack up to your other recommended brands?

Charlie Mason
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I’ve shot both the Core15 and the .308 version, which I can’t remember what they call it? I’ve shot several Areo’s including this upper which I do own. The Core rifles just don’t have what the AREO’s do in design and basic looks to the rifles. The Prices on Core’s are under $400 in some places online. The Core rifles I felt like I was getting less or just right on what I would have paid for had I bought it. The AREO it feels like it’s better built & it doesn’t leave you feeling like you got a cheap… Read more »
Ryan B.
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New AR15 owner here and I just happened to buy an Aero rifle with this upper (Called the Quantum). Choose this over the Saint since I do not want to be a Beta tester for their rifle.

I was able to buy a Magpul Front and BUS with this and unfortunately, my Front sight does not flip down from not having any room to do so though my BUS does work as intended.

Despite that, I am happy that I choose an Aero rifle over my list of other models!

jason
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Hi Eric,
I am looking into buying my first ar-15. I have a military background, Marines, so I’m happy with fixed A2-style front, I’ll be shooting iron sights most of the time. This rifle is for self defense with plinking fun gun. I would like to shoot steel ammo, since I’m on a budget.
Any AR-15 recommendations for me?

Sean
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Like the video footage,etc. I’m a budget shooter since now I’m a retired policeman and would like to know what range you use and is it open to Active/Retired Police like yours truly. Currently shoot at Angelus

Really appreciate your articles.

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