What happens when you mount a premium suppressor to a basic rifle? I put a Sig Sauer HEXIUM on an AK to find out.
As a gun writer with a predilection for outdated firearms, sometimes I find myself a bit out of my element. Case in point, Sig Sauer recently sent me one of its new HEXIUM762 suppressors to test out, and I didn’t really have an appropriate host for it in my gun safe.
HEXIUM suppressors are state-of-the-art, 3D-printed, low-backpressure cans that really belong on a modern carbine. Something like a Sig MCX. But I don’t have one of those, or any .30-caliber gas gun from this century.
So, what did I do? I embraced the mismatch, and mounted it to the cheapest, most basic AK I own: a WASR 10/63 underfolder.
I paid about $700 for this AK back in the day, and the HEXIUM762 retails for $200-$300 more than that. It’s pretty common to find rifle setups with optics worth more than the gun they’re mounted on, but you don’t see that as often with suppressors. Sometimes, it’s fun to put lipstick on a pig, so I figured why not.
Turns out, these two made for an awesome pair.
HEXIUM762 Specs
Model: HEXIUM762
Caliber: 7.62 NATO
Material: Titanium
Diameter: 1.75 Inches
Overall Length: 6.2 Inches
Weight: 11 Ounces
HUB Compatible?: Yes
Factory HUB Mount: 5/8×24 Direct Thread
MSRP: $999.99
Pros
- Super quiet
- Very low backpressure
- Light and compact
Cons
- Hard to remove the factory HUB mount
On The Range With The Sig HEXIUM
So, what’s special about Sig’s HEXIUM line? A lot, actually.
HEXIUM suppressors feature 3D-printed titanium (or Inconel in the case of one of the 5.56 models) cores with some very intricate and precisely engineered baffle geometry. Every suppressor manufacturer these days claims to use the latest and greatest technology to design its cans, but in the case of the HEXIUM762, the proof is in the pudding. This thing is stupid quiet.
More than that, it’s a very low-backpressure design, something that’s immediately noticeable once you’re behind the gun. If you’ve shot a lot of suppressors, especially on innately overgassed AKs, you know what it’s like to try and make good hits while floating in a cloud of toxic gas. With the HEXIUM762, you can breathe easy, even with a Kalashnikov.
I put about 500 rounds through the HEXIUM, a mix of Wolf 124-grain FMJs and Detroit Ammo Co. 220-grain subsonics. The setup cycled the subs perfectly, and they made for an extremely pleasant shooting experience. I tried both loads without ear protection, and the loudest part of shooting the subs was the action cycling. Even the supersonic ammo was inoffensive.
Outside of the shooting experience itself, the HEXIUM762 made for an incredibly unobtrusive addition to the rifle’s muzzle. It’s reasonably compact at just 6.2 inches long, but more importantly, it only weighs 11 ounces thanks to its titanium construction. I shoot a lot of AKs, and I barely noticed a difference in handling with the HEXIUM installed. Some suppressors feel like a brick strapped to the end of your gun and can seriously hinder your ability to transition between targets or keep the weapon shouldered for prolonged periods. Neither of those were true of the HEXIUM.
The low weight is an upside of titanium cans, but as is true with all things in engineering, there are some tradeoffs as well. One of those is that they definitely heat up faster than stainless steel suppressors, but they also cool off faster, too. I dumped two magazines through the HEXIUM762 and measured its temperature at a bit above 700 F at its hottest point. Since it’s best to keep titanium cans below 800 F, this just means that the HEXIUM isn’t ideal for high volume of fire shooting, but that’s true of any titanium suppressor. For most shooters, the benefits of titanium will greatly outweigh any limitation imposed on your firing schedule.
Another quirk of titanium is its propensity to spark. The HEXIUM762 did spark for me, but much less than some other titanium suppressors that I’ve shot. It only sparked after getting very hot, and it wasn’t very much. Unless you’re shopping for a can to get into nighttime gunfights with, I wouldn’t worry about it.
Mounting The HEXIUM762
Before I could shoot the HEXIUM, I had to get it mounted to my AK, and that proved to be a bigger headache than I was expecting.
You might be thinking that the issue was caused by the AK’s weird 14×1 LH thread pitch, but it wasn’t. HEXIUM suppressors are HUB-compatible, and there are plenty of 14×1 LH HUB mounts on the market. I got a 360HDM from JMAC, and it proved to be excellent.
The issue was actually removing the original 5/8×24 direct thread mount that the HEXIUM762 came with.
Sig installs these guys tight, and I’m not the only one who’s noticed this. You can find a lot of discussions online filled with tips on how to remove them. Like many problems, however, the solution was simply using the right tools.
In this case, it was a special tool that Sig sent me that grabs the three lugs on the front of the HEXIUM. Putting the can directly in a vise and cranking it down would damage it, but this tool allows you to tightly secure the can in a vise without putting pressure on the suppressor body itself.
Even with the HEXIUM properly secured, a normal suppressor tool couldn’t provide enough leverage for me to break the HUB mount loose, so I had to bust out a big ass pipe wrench. With that, and a pretty serious application of strength, I was able to remove it. After that, installing the new JMAC mount and suppressor was easy.
As for the tightness of the original mount, I’m of two minds about it. On one hand, if I were planning on only using the can with the 5/8×24 direct thread mount, I’d be very happy about it. Nobody likes their suppressors coming loose on the range, and the substantial torque that Sig uses to install its mounts almost entirely ensures that that will not happen. On the other hand, anyone looking to swap the original mount for something else better be ready to apply serious elbow grease.
The biggest problem I have with the situation is that I couldn’t actually find the special Sig vise tool for sale anywhere online. Sig only sent it to me after discussing my difficulties with them. Based on some of the creative hacks I’ve seen people on the internet be forced to devise to remove theirs, I really think that Sig should be selling this tool, if not just including one in the box. At the very least, I think the product page should mention how tightly the original is installed and provide a link to where the tool can be purchased.
As long as you’re aware that swapping mounts will take some effort, you shouldn’t be dissuaded from getting a HEXIUM. The can’s performance completely outshines the difficulty of removing the factory HUB. Better yet, if you’re going to put it on a gun with a 5/8×24 muzzle, just use the original direct thread mount and don’t sweat it. People these days forget that direct thread mounting has a lot of advantages, and as long as you properly torque it to the gun’s muzzle, it should never come loose.
Parting Shot
Despite how overly regulated suppressors are, they’re actually very simple devices, and it’s not hard to make a basic one that works OK. Designing one that excels in a single area, like noise reduction or minimized gas blowback, is harder, but doable.
What’s much more difficult, and a truly impressive feat of engineering, is designing a can that excels in more than one area. And that’s what Sig Sauer has achieved with the HEXIUM762.
It’s impressively quiet, one of the least gassy cans I’ve shot, and it does it all while being barely noticeable while mounted on a rifle.
It proved to be an excellent match for my AK, but let’s be real, most HEXIUM buyers will be mounting it on something a little more 21st century. With how well it reduced blowback to the face for my crusty old Romanian underfolder, I can only imagine how well it would perform on a more modern rifle with adjustable gas. Frankly, I may have to get something more modern for it to live on now, as it feels like a bit of a waste of potential to keep it mounted on this WASR.
Outside of the effort it took to remove the original HUB mount and the seeming unavailability of Sig’s special vise tool, I have nothing to complain about.
It’s a seriously awesome can.
Gear Notes: JMAC 360HDM HUB Mount
While JMAC specializes in AK stuff, the company has plenty of accessories that could be useful for other platforms. For example, the 360HDM HUB Micro mount that I used to mate the HEXIUM with my AK. It’s offered in several thread pitch options that range from weird to generic.
Not only is it a suppressor mounting solution, but it provides additional benefits whether a can is currently mounted or not. When a can is mounted, it acts as a sacrificial baffle to protect and prolong your suppressor. When no can is mounted, it acts as a muzzle brake and flash suppressor. I like that this concept enables you to remove your can for transport while keeping your rifle ready to shoot without risking damage to your muzzle threads.
Plus, it’s available with the cool smoked brass finish option that you see pictured in this article.
More On Suppressors
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Great article. Thanks. I’m looking at this suppressor now for a .556
Thanks