Aero Precision has made a name for itself for its unique manufacturing capabilities from its homebase in Tacoma, Washington. They’re changing the game with their custom forged and designed AR15 stripped lower receiver. It’s now become the standard for higher tiered stripped lower receivers.
Don’t be fooled by the aesthetics of the integrated thumbguard. This lower packs more features than meets the eye.
Features of the M4E1
The photo below speaks for itself but we’ll get into the details of it. As an experienced AR15 and AR10 builder, I have to tell you that Aero Precision has fixed some of the most nagging issues related to building an AR15.

Integrated Trigger Guard
The feature speaks for itself. The trigger guard is manufactured as a part of the lower receiver. This is great for anyone who might accidentally use their hulk strength when installing the trigger guard pin to their stripped lower receiver. It’s a small improvement with big impact.
Threaded Bolt Catch
This was always the second most difficult installation for me (the trigger is always the first). Instead of installing a pain with a punch, you’ll have a threaded bolt catch. This comes out with a small allen key and is easily taken out or put back in.
Flared Magwell
This may seem pretty standard but you’d be surprised. If you ever pick up an AR without a flared magwell, you’ll notice a huge difference (or hindrance we should say). A flared magwell should be standard and is a pain when it isn’t.
Upper Tension Screw
The upper tension screw allows the gun owner to adjust the “wobble” or fit up the upper and lower receivers when assembled.
Threaded Takedown Pin Detent Channel
A lot of parts of the M4E1 assembly can be tricky and make many new AR15 owners feel they’re not assembling the receiver properly. In all stripped lowers, a detent pin is inserted in the rear of the receiver and holds the safety in its proper channel or groove.
This pin is usually held in by a spring that butts up against the buffer tube’s end plate. This spring is long and susceptible to damage during assembly. The detent channel and screw remove the potential damage. It also makes it easier to change out buffer tubes.
Milled and Marked Safety Selection
The Aero Precision M4E1 lower has a specially milled safety selector marker. Your typical AR15 is milled to accept full sized safety selector while the M4E1 is milled to accept both full sized and short throw safety selectors.


Why do the features matter?
You might argue that these features don’t matter. For people familiar with the Aero Precision M4E1 lower, they know it’s the small details that make the difference. These features can turn the building process from a frustrating one to a favorable experience.
Read: What’s the Best AR-15 Stripped Lower?
I cannot tell you how nerve wracking it can be to assemble your first AR15 lower receiver. You pay for it, you get your background check, and you end up:
- Mar the receiver
- Break the trigger guard
- Lose a spring
- Shoot a wobbly upper and lower receiver
Cost versus other brands
You’ll pay about the same price for an Aero Precision M4E1 lower compared to many other brands out there. Even for brands of the same quality, you should expect to receive a superior product over other imitators. The Aero Precision M4E1 lower retails at $124.99.