Simpler is Better: The Aero Precision Slick Side Upper Receiver

Last Updated on May 9, 2024.

I’m not a big hater of the forward assist. Recently, though, the forward assist has gotten rather unpopular. If you hate having a forward assist, the Aero Precision Slick Side Upper Receiver offers a solution: get rid of the forward assist.

On a rifle caliber AR-15 (.223/5.56mm, etc.), the forward assist has a purpose. Whether or not you need anything to serve that purpose is debatable. But there is a purpose.

However, having a forward assist on a pistol caliber AR-15 makes no sense. Most pistol caliber bolt carriers don’t even have forward assist notches. So I will admit that there’s no reason to put a forward assist on EVERY SINGLE AR-15 rifle.

Which means that the Aero Precision slick side upper is the most appropriate upper in certain contexts. And, for those contexts, the Aero Precision slick side upper is a remarkably high quality component.

But, regardless of why you prefer a slick side upper—because you don’t like the forward assist or because you just don’t need it on that particular rifle—I’d recommend that you at least consider using the Aero Precision slick side upper.

And I’ve actually used this upper receiver. So I’ve got some evidence to back up my recommendation. Here’s what I know about the Aero Precision slick side upper.

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Aero Precision Slick Side Upper Receiver Review: Fewer Parts is (Often) Better

Say what you want about Aero Precision components (yes, the gas ports on their barrels are huge. No, their Atlas handguards aren’t great if you want to mount sharks with laser beams on your rifle), Aero Precision receivers are awesome.

As far as I know, no other company produces receivers that deliver as much value as Aero Precision receivers.

So the Aero Precision Slick Side Upper Receiver is one of the best options if you’re looking for an upper receiver without a forward assist.


If you’ve read any of my upper or lower receiver reviews, you know that I’m stickler when it comes to the anodized finish on a receiver.

I’m not a fan of slightly gray anodized finishes. And I prefer a smooth, semi-matte finish. Rougher matte finishes aren’t my favorite.

That’s why I give the finish on the Aero Precision slick side upper two thumbs up.

Before I rave about it, I will concede that you can get receivers with smoother, glossier finishes. But they cost notably more than an Aero Precision receiver. In terms of cost efficiency, the Aero Precision finish takes the cake.

With that, I will rave about the finish.

The finish on this upper receiver is dark black. There’s none of the graying that’s characteristic of many budget upper receivers.

Also, the finish is relatively smooth. The surface has a satin or semi-matte finish. It’s not super smooth and glossy. But it’s smooth enough to have at least a little bit of sheen.

Lastly, in my experience with Aero Precision receivers, the anodized finish is super durable. I’ve seen Aero Precision receivers get beat up pretty badly. And the finish held up remarkably well.

Also, the finish on the brass deflector hasn’t started to wear off at all. Yes, brass residue sticks to the brass deflector. But the constant brass beating hasn’t started to wear through the black finish, yet.

However, my slick side upper has a 9mm barrel. And I don’t think 9mm casings hit the brass deflector as much as 5.56mm casings.

It’s obviously not invincible. But the surface hardening and the black finish is clearly done well.

 All in all, the finish is excellent. Enough raving about that.

Fit and Parts Compatibility

The parts compatibility is kind of a moot point because there’s only one part on an upper receiver without a forward assist.

This upper receiver accepts standard ejection port cover doors. And if you get the assembled version, the ejection port cover comes installed. The installed ejection port cover snaps shut super positively. It’s a well fitted part.

Enough said about parts compatibility.

However, the fit is very nice. I’ve tested this upper receiver on a handful of lowers just to see what the lower receiver fit is like.

Aero Precision seems to have gotten the fit right. On every lower receiver I tried, there was very little slop in the upper and lower receiver fit. And there was basically zero slop when I mounted it on my Aero Precision AR-15 lower, even before I adjusted the teflon tension screw.

Overall, the fit is precise. And it’s not difficult to push the takedown pin in and out. Assembly and disassembly is easy. But there won’t be much wiggle when your rifle is assembled.

The threaded upper receiver extension is also precisely machined. The barrel I installed in this upper receiver fit nice and snug. No slop in the barrel fit. So there was no need to get aggressive when I torqued the barrel nut down.

Lastly, the picatinny rail has laser etched T-markings. And the slots are cut to the proper spec. I put a picatinny accessory into every slot, just to be sure, though.

Overall, this upper gets high marks for fit.


I’m not sure what it is about upper receivers without forward assists. But they seem more prone to function issues.

It’s probably just my perception. I deal with fewer slick side upper receivers than I do standard uppers. So one or two uppers with problems make up a higher percentage of the slick side uppers I see.

My experience aside, the Aero Precision slick side upper has a really strong dry lube coating on the interior. If you shine a flashlight into the bolt carrier channel, you can see the polished finish.

And it seems to work. I used this upper receiver for a 9mm AR rifle. This rifle has run flawlessly from the very first round. I’ve had literally zero malfunctions in my 9mm carbine.

Now, I know that the other components in the rifle have a lot to do with that. But, clearly, the upper receiver is doing its job.

Also, the dry lube finish inside this upper receiver is easy to clean. I’ve cleaned enough rifles to last me several lifetimes. So I appreciate an upper receiver that basically just wipes clean.

Short bit about the top rail: it’s pretty much a standard picatinny rail. It’s got laser engraved T-marks and lightening cuts.

Nothing special. But it works just fine. I had no issues mounting or zeroing my optic on this upper receiver, which is exactly what I want from my upper receiver.

In my estimation, the performance is normal. By that I mean that this upper receiver performs well enough that you basically won’t notice it. It just works.

If you're looking lower receiver which is a great fit for you, Aero Precision got your back.

Breaking Things Down Shotgun Style

I pretty much exclusively use Aero Precision receivers at this point. It’s not that there aren’t other good receivers out there. There just aren’t any that are as cost efficient as Aero Precision receivers.

If you’re the type who prefers an upper receiver that has no forward assist, this Aero Precision Slick Side Upper Receiver could be your default upper receiver. As far as I can tell, this upper receiver won’t give you any problems. Just put your rifle together. And this upper receiver will do its part to ensure your rifle runs the way it should, which is exactly what you want from your upper receiver.

That’s why the Aero Precision Slick Side Upper Receiver is such a cost efficient choice. So spend away on this one.

And while you're at it, you can read on our Aero Precision Buffer Tube Review.