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Silencer Shop Authority: AAC Halcyon Review

In a world full of quality .22 silencers, few companies have displayed anywhere near the same sort of staying power as Advanced Armament Corp. (AAC). Over the years, the folks at AAC have brought to market a slew of popular rimfire choices including cans like the Aviator 2, the Element 2, and the Prodigy. However, despite these successes, other companies have recently begun to encroach upon AAC’s leading status with modular, easier to clean designs that perform as well as, or better than AAC’s offerings. In response to this market pressure, AAC announced a new .22 suppressor – the Halcyon – at the NRA Annual Meetings earlier this year.

With the Halcyon, the folks at AAC have essentially taken their fantastic Element 2, upgraded its baffles, added an interchangeable mount, and made the whole thing modular. At least on paper, it’s a heck of an improvement over what was already one of the top performers in the category. Thanks to our friends at Silencer Shop, I recently spent a few weeks with the Halcyon and am ready to share some thoughts.

AAC Halcyon Multicam Pouch
Look, I've said this before, but I really appreciate it when companies send their cans in nice boxes and/or with quality pouches. Customers wait an eternity for these things so presentation is worth something. Here, the Halcyon is pictured with the Multicam pouch that AAC ships it in.

Size & Weight

The Halcyon’s full configuration measures 5.25” long and weighs in at a true 6 ounces. Like most of its peers, AAC’s newest suppressor is 1” in diameter. It’s effectively the same size as AAC’s Element 2, but just a bit heavier. Compared to the rest of the market, the full Halcyon falls right in the middle of the size spectrum. After having found Rugged Suppressors’ modular, fully-stainless Oculus 22 to be a little too heavy for my tastes, the Halcyon feels fantastic.

AAC Halcyon 90T Flash Hider
The shortened Halcyon is less than an inch longer than AAC’s 90T flash hider.

Removing the front module shortens the can to just 3.4”. It also lightens the unit to right at 4.5 ounces. It’s such a compact package that the Halcyon is barely larger than a long flash hider or muzzle brake and it virtually disappears on my SIG 522.

AAC Halcyon


5.25", 3.4"




6 oz, 4.5 oz



7075 T6 Aluminum

17-4 Stainless Steel


1/2-28 Direct Thread

(Other Pitches Available)



Materials & Design

The Halcyon is made of several different materials. The main tube is titanium, while the forward section features a 7075 aluminum housing. Both parts are then finished with Cerakote. The baffles are all titanium. Finally, the thread insert is 17-4 stainless steel. Quite the mix indeed, but because the baffles are titanium, they can be cleaned with harsh chemicals like Hoppes #9, the “dip”, and ultrasonic tanks – just keep the cleaners off the aluminum portion of the tube.

Included with the Halcyon is a ½-28 threaded insert. This should be all most people need but the part is removable for those with unusual threads. Some European rifles and handguns are made with ½-20 threads. AAC has an insert coming in that pitch (as well as a few others) and a QD attachment system looks to be around the corner as well.

AAC Halcyon Mount
The Halcyon’s included 1/2-28 thread insert is removable and the company offers other, more obscure pitches. They’re also working on a QD system.
SIG 522 Muzzle Device AAC Halcyon
Popping the Halcyon on a rifle, like my SIG 522, adds barely more length than a typical flash hider.

Shortening the Halcyon is as simple as unscrewing the two body segments and moving the front cap from the forward module to the main tube. The three baffles inside the forward section are captive until the cap is off, at which point they will slide easily out the front of the tube. The main unit’s four-baffle stack can be dumped any time the front module and end cap are absent.

Shorten AAC Halcyon Front Cap
Shortening the Halcyon requires simply unscrewing the front module and moving the end cap to the main body.

Taking the Halcyon apart for cleaning is very easy – largely because the baffles shield the outer tube from debris. While the K-style baffles are operationally similar to the ones in AAC’s fantastic Element 2 and Aviator 2 suppressors, the Halcyon’s add a rear-facing outer skirt that encapsulates the preceding baffle’s cone and prevents fouling on the suppressor’s tube. The end result is that the baffles perform just as well as those in the Element/Aviator (fantastic) and they’re easier to remove for cleaning. Even after a few hundred rounds, the baffles slide out easily. The only real downside is that the skirts add some weight.

AAC Halcyon Disassembly
The Halcyon disassembled into functional groups - the main body on the left and the front module on the right.

While reassembling the Halcyon, it is important to note that the baffles are keyed. By this, I mean that each baffle’s cone is notched to accommodate a flat on the face of the subsequent baffle. This helps to establish alignment of the baffle structure. The fitment isn’t tight enough to lock the baffles together, but the keyed design ensures that the baffles go back together the same way each time, with the gas ports aligned for optimum suppression and repeatable point of impact (POI) shift.

K-Baffles AAC Halcyon
K-Baffles are at the heart of the Halcyon, but these have skirts that shield the out tube of the suppressor from debris and keep the can easy to take apart.

Range Report

There are a LOT of really excellent .22 suppressors out there, but few companies have held a top spot for as long as AAC. For years, the Element 2 has been well-regarded as one of the quietest rimfire cans on the market and it looks like the Halcyon is set to join it at (or near) the top of the field.

AAC Halcyon Walther PPK/S
I just love the look of the Halcyon on my Walther PPK/S .22 LR. Here, we see the full-size format, which performs far better than the short configuration on a pistol.

I know I’ve said this for a couple of other cans lately, but the Halcyon may well be my favorite .22 silencer to date. Previous leaders included the Q El Camino and AAC Aviator 2, but the latter was all-aluminum and both lacked modularity. The Halcyon performs as well as both, adds dual-length adaptability, and uses tough, easy-to-clean materials.

Mounted on my SIG 522, the Halcyon sounded superb and very reminiscent of those aforementioned favorites. On this host, there was not a significant difference between the full and short configurations. This is fairly standard for .22 cans on rifles as the 16” (or greater) barrel provides ample time/space for powder burn. Both formats were clearly hearing safe and with the difference being so negligible, the obvious choice was to use the short configuration for the bulk of my rifle shooting. As I mentioned earlier in this review, the short Halcyon is effectively the same size as a large muzzle brake or flash hider, but to be more specific, it is less than in inch longer than AAC’s own 90T flash hider. On a carbine like my SIG, it’s a fantastic fit.

SIG 522 AAC Halcyon Suppressor Short
The shortened Halcyon is just flat awesome on a rifle like my SIG 522

With the Halcyon attached to my Walther PPK/S .22, the story changed a bit. Here, the short version still put up an impressive showing, but the difference between it and the full configuration was more apparent. I could certainly still use the short configuration without any discomfort, but the long format was much quieter – again, one of the quietest .22 cans I’ve tried. This result was predictable and in line with other modular suppressors I’ve tested. Short pistol barrels mean higher muzzle pressure – even with rimfire ammunition. In this case, the full-length Halcyon more effectively slows and captures the gas that trails each bullet and therefore, the full Halcyon is the way to go with handguns.

Short AAC Halcyon Walther PPK/S 22 LR
The short Halcyon handles incredibly well on a handgun, but it is noticeably louder in this configuration.

In the 2+ years since I began reviewing suppressors, I’ve used a handful of otherwise excellent .22 cans that I simply would never purchase due to poor first-round performance. First round pop (FRP) is the product of trapped oxygen inside the suppressor and it affects all silencers to some degree. However, thanks to the relative silence of suppressed .22 LR, it’s most apparent in this setting. Fortunately, the Halcyon exhibits almost no FRP – almost. On my PPK/S, the FRP with the Halcyon was just barely loud enough to be noticeable. At most, the first shot was just 3 dB louder than subsequent rounds. Beyond the Halcyon’s excellent overall sound quality, its minimal FRP has me seriously considering a future purchase.

To test POI shift, I set up a target at 50 yards and fired subsequent 5-round groups – one suppressed and one unsuppressed (I did not test the short configuration). At this distance, the suppressed group sat almost exactly 1” below the unsuppressed rounds. This translates to 2” at 100 yards, or two minutes of arc (MOA).

SIG 522 AAC Halcyon Long
The short configuration steals the show, but the long Halcyon is no slouch on a rifle. It also isn't unwieldy.


With all the hot new silencer companies that have sprung up over the past two or three years, it’s easy to forget about established brands like AAC. While the days of free cans for tattoos and other sorts of ridiculousness may be long past, AAC’s lineup is still loaded with plenty of compelling options that are well worth some consideration. The Halcyon stands out as one of the strongest entries in this group.

As .22 suppressors go, the Halcyon has just about everything. It employs a baffle design similar to AAC’s other top-performing .22 silencers, but adds additional measures to prevent tube fouling. The materials used in the Halcyon ensure that it is both light and durable, leaving plenty of cleaning options open for high-volume shooters. Finally, and perhaps most significantly, the Halcyon’s modularity adds considerably value. To be honest, unless something comes out soon that totally blows my socks off, I’ll be adding a Halcyon to my safe on a more permanent basis.

Those who are interested in grabbing a Halcyon for themselves should scoot over to Silencer Shop. There, you’ll find the can for just a hair above $400, but the price will depend on whatever your favorite Powered By dealer has chosen to ask.


This has been a review of products provided by and sold at Silencer Shop. All opinions are my own.

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