Amtac CQB Reflex Suppressors: More Quiet In A Shorter Package

The Amtac CQB reflex suppressor gets you more quiet with less overall length by mounting over the barrel.

January 02, 2024 By Patrick Sweeney

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Suppressor makers are always updating things, improving things, and changing names. Amtac has been in business for 35 years, and they are a supplier for aerospace and defense industry manufacturers. If you make parts that go into space, then bringing that level of precision and attention to detail to making suppressors has advantages. Amtac is no stranger to the idea of continual improvement, and they have improved their 5.56 suppressor to the point that it has a new name. But even in the digital age paperwork takes time, so until that new one arrives here at Gun Abuse Central, I’ll give you the lowdown on the older model, because it is still a good one. The Amtac CQB is a 5.56 suppressor that knocks almost 30 dB off of your muzzle report, and only adds less than four inches to your barrel’s length. I thought that last part would get your attention. Four inches, you ask, how do they do that? Simple: it is a reflex design. Reflex? Yes, the idea is simple, attractive, and effective. You make the suppressor with the mount (in this case a direct-thread attachment) and you locate it halfway up the interior of the suppressor. Then, you make the rear part of it, the portion behind the first, blast, chamber, hollow. Yep, the portion that slides over the barrel is a really big expansion chamber behind the blast chamber, and you get a lot more interior than the mere (in this case 3.7 inches) extra length the suppressor adds. Now, there are costs and limitations when you go this route. Hey, life is like that. The late science fiction author Robert Heinlein put it best: “There ain’t no such thing as a free lunch.”

amtac-reflex-suppressor-02 — The CQB has the mount threads in the middle, and the tube slides over the barrel before you tighten it in place. The net result is less than four extra inches, so a carbine becomes no longer than a rifle. No shift in point of impact, and plenty of accuracy to be had.

The expansion chamber area has to be both sturdy enough to hold the pressure, and strong enough to not be dented, bent crinkled or creased in use. That adds weight. The design puts a strict limit on barrel diameter, since the suppressor has to slide over it. No bull barrels, but who uses those anyway? There’s no real way to make it a QD mount system, as you need some sort of locking system, and that means cutting through the exterior of the tube someplace in the middle. But not everyone wants or needs a QD mount. And lastly, a reflex suppressor such as the CQB has a bit more insurance against baffle strikes. Since the baffled section is only 3.7 inches long, compared to seven, eight or nine inches of non-reflex suppressors, a reflex suppressor is a bit more forgiving of misalignment. Now, I’m not saying you can just slap a CQB on your barrel and have at it, but if your threads are a bit off, and you have found you can’t get a full-length suppressor to line up, you might find an Amtac CQB lets you use that barrel without a radical re-machining. But the benefits are obvious: a carbine becomes no longer than a rifle. If the barrel is long enough to keep the back plate of the CQB from touching the gas block, you can make an SBR no longer than a carbine. And the extra interior means more dBs knocked off the muzzle blast, and less blowback even before you start taking other steps.

I’ve thrashed the CQB on a few different rifles in the rack, a couple of piston-driven ones, a bunch more that are DI, and it has not given me problems on any of them. I saw no point of impact shift on all but one rifle, and that wasn’t Amtac’s fault. I tracked that down to a barrel nut that was tight enough to hold zero until you hung a suppressor on it. And I suspect that there are other ARs out there with the same situation. I’ve had that as a mental note in the back of my head on any AR build or overhaul ever since: while the mil-spec barrel nut torque allows for a low end, the low end might cause problems when you park extra weight on the barrel. So, I now got to put extra effort to fit a barrel nut on at the upper end of the torque limits, and barrel nut alignment, to hopefully forestall that problem. That’s a bonus that came about from testing the Amtac CQB, thanks Amtac. The CQB offers one more advantage, and that is, with the right spanners you can take it apart for cleaning. This means my CQB, should I ever pry it off of the host rifle it is on, can be used on a rimfire rifle. Rimfire ammo is incredibly filthy, and I’d never use a sealed 5.56 suppressor on a .22LR rifle. But the CQB gives me that option, since I can take it apart, throw it in the ultrasonic cleaner, and get the gunk off.

amtac-reflex-suppressor-03 — Here is the CQB disassembled, showing the one-piece baffle stack, and how you can use a centerfire rifle suppressor on a rimfire rifle and not end up regretting it.

Since I last got a shipment of Amtac suppressors, they have had some changes. The baffle stack is still a single piece of CNC machined metal, inside of a seamless tube, and they are still full-auto rated. They still offer suppressors in .22LR, 9mm, 5.56, .300 Blackout, 6.5 and .30 Cal. However, in looking over the specs, I see that they have managed to make the sound suppression more effective, and the weights lighter. And they have adopted a new look, with the suppressors bearing names of Polynesian heritage, and each with a laser-etched logo also of Polynesian heritage. (I might point out that as best I recall from readings of history, that it was only the Maori who managed to break a British infantry square without the use of artillery. Just spears, clubs and knives. Tough dudes.) As I said, suppressor makers are always improving things. Amtac, a defense industry manufacturer with ISO9001 certification is no exception. However, lighter weight and more decibels knocked off the muzzle blast are not reasons enough to ditch my existing CQB. No, that one is going to stay on the carbine it finally found a home on, because it works, it hits to the sights, and it doesn’t blast me in the face. But I’m really looking forward to a side-by-side comparison of the CQB with its successor, the Koa. Be sure to check out their website for this and other interesting suppressors.