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Swampfox Kraken & Wolverine: Enclosed Emitters & Fancy Slides [REVIEW]

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Swampfox has been around for more than a minute now and has quickly become known as a maker of some pretty solid optics that retail for a respectable price.

I’ve watched Swampfox over the years and what stood out to me is their willingness to innovate and change. They don’t make the same thing everyone else does; they actually listen to feedback and make things better.

While I’ve bought some optics from Swampfox before, this was the first time they’ve sent me anything to review.

I’ve been working on a faux-Roland Special EDC CCW Glock for a few years, trying to find the perfect combination of parts, so I was pretty excited when I saw the Swampfox Wolverine slide ticks some major boxes I’ve been looking for.

Closed emitter red dot optics are undoubtedly the next evolution of pistol sight technology, but most of the options on the market are crazy expensive. Being a life-long cheap-ass, the hope of finding something less expensive in the Kraken intrigued me.

Throw this all together into my Faux-Special, EDC it for a couple of months, take it to the range a dozen times, and run a couple of thousand rounds through it all, and here we are.


Kraken Enclosed MRDS

  • MOA Adjustment: Dial
  • Dot Size: 3 MOA
  • Magnification: 1x
  • Lens Diameter: 16mm
  • Illumination Positions: 10
  • Brightness Adjustments: Up/Down Digital Press
  • Shockproof G Forces: 1500Gs
  • Waterproof: 1 Meter/ IPX7
  • Battery Type: CR 2032
  • Max Battery Life: Approximately 2 Year Real World (Shake ‘N Wake)
  • Dimensions: 1.85”(length) * 1.38” (width) * 1.27”(height)
  • Weight: 2.5oz without battery
  • Lens: “Multi-Coated Ruby Red – Red Dot or Multi-Coated Silver – Green Dot”
  • Specialty Coatings: Anti-fog, hydrophobic, anti-scratch
  • Parallax: Parallax free @33 yards
  • Eye Relief: Unlimited
  • Mount Type: RMR Adapted / MOS Adapted
  • Chassis: 7075 Aircraft grade aluminum
  • Windage/Elevation Movement Range (MOA): 45 MOA/ Total 90 MOA Range

Wolverine Glock 17 or 19 Gen 3 Slide

  • Slide Model​: “Glock 17 or Glock 19​”
  • Compatibility​: Glock Generations 1-3
  • Material​: 416 Stainless Steel Billet
  • Finish: “Hand Distressed Cerakote – Battleworn Gray or Nitride – Graphite Black”
  • Optic Cut: RMR Footprint
  • Iron Sights: Fiber Optic or Stealth Tritium Night Sights
  • Included Internals: Channel Liner


Micro red dots have been around for a while now and have become more or less accepted on pistols. 

I’ve EDC’d an optic on my CCW pistol for close to 5 years now, and I wasn’t much of an early adopter at all. Special forces have been using them for about 10 years, but even ‘Big Army' is making the move toward putting optics on duty pistols now. Major law enforcement departments, who are always the last to adopt anything cool, like the LAPD are even fielding optics on their duty guns.

But through all of that, there has basically been one kind of red dot used – the open emitter.

“Open” means that the LED that makes the dot is “open” to the elements. While set recessed and mostly protected as well as it can be, the LED is still “open” to the world and all that is in it.

Swampfox Liberty with an open emitter design

In theory, the LED can be damaged or, more likely, obstructed by rain, mud, dust, snow, etc.

For a CCW, this is rarely an issue since part of being “concealed” means keeping your weapon (and optic) covered up.

But for duty guns, or really any open carried gun, this becomes a more real concern.

Enter: Closed Emitters

As you can guess, “closed emitter” optics means the LED is enclosed in the body of the optic. This requires two panes of glass, a bulkier design, and other manufacturing considerations like purging the space between the front and rear glass of air to ensure it won’t fog.

Closed and sealed up tight

Downsides? Increased cost, larger size, and a footprint too large to fit in the standard RMR, DPP, or other optic footprints.

Upsides? More durable and cannot get fouled or obstructed with anything.

Wolverine Slide

It seems almost everyone makes a Glock slide these days and having tried out a lot of them, there normally isn’t much practical difference. 

Thankfully, Swampfox isn’t content to do the same thing everyone else is doing and actually puts features and changes into their Wolverine slide that make a difference. 

There are the standard features we should expect in an aftermarket slide, like front and rear slide serrations, replaceable sights, and a cut for an RMR footprint optic.

The big feature that makes the Wolverine different is where they place the rear iron sight on the slide. Most slides put the rear sight behind the optic so that when you’re looking at the target, you see rear sight, optic, front sight.

Swampfox moves the rear sight from behind the optic to in front of the optic, and this makes a huge difference. Opponents of this change will say that it obstructs the iron sight picture and reduces the sight radius. But those people are silly and can be ignored.

If you’re going to run an optic on a pistol, I’m a huge fan of putting the rear iron sight in front of the optic.

I hate looking at my irons when I’m using a dot, and for years I’ve used an EDC slide that didn’t have irons at all. By placing the rear sight in front of the optic, I now have an unobstructed view and a cleaner sight picture. It also places something protective in front of my optic that will take some of the beatings if I rack the slide off hard objects.


The Wolverine slide conceals like any other Glock 19 slide. There is nothing too weird or hanging out or anything of that nature. It just sits in the holster and waits for when it is needed.

For the vast, vast majority of the time, the Kraken is totally unnoticed while carrying. But there has been once or twice where I felt the corner of it pressing into my side. The corners are rounded off nicely, and the entire housing is very smooth, so it wasn’t really uncomfortable at the moment. It was only when I moved that I noticed it had been there but was no longer there.

To be fair, this only happened when I was driving for 5+ hours. 

That said, I’ve never had this happen when using a smaller red dot like a Trijicon RMR or Holosun 507c. I’ve never carried another closed emitter like the Aimpoint ACRO, so I can’t give an apples-to-apples comparison. I suspect that I would have the same issue.

Was this a problem? Not even slightly, really. But it happened, and I felt I should mention it.


When first mounting the Wolverine slide, I wasn’t sure I was going to love it. Personally, I love front serrations, and I want my serrations to be super crazy aggressive. If the serrations don’t hurt a little when you touch them, they aren’t aggressive enough in my book.

The Wolverine’s front serrations are decent, but in dryfire, I was a little worried about them.

Most of that has gone away now that I’ve gotten time and rounds through the slide. I would still like it if they were more aggressive, but they are definitely more aggressive than I first thought they would be.

During drills and shooting courses of fire, I never had an issue racking the slide using those front serrations, even when my hand was wet with sweat. The rear serrations are the same type of cuts, but I’m not really a rear serrations kind of person, so I didn’t notice them as much.

From what I’ve read online and heard talking to other shoots, their main concern with closed emitter optics is that the window is smaller. And they’re not entirely wrong, the window is in fact smaller.

The Kraken has a 16x16mm lens, for a closed emitter optic, this isn’t uncommon, the Aimpoint ACRO has a 16x16mm lens, also.

Compared to a more standard red dot like the Trijicon RMR or Holosun 507c, which are 16x22mm and 16x23mm, the Kraken’s window does feel a little small in some respects.

When you’re target focused, the size difference doesn’t matter. The sides of the optic blur away, and all you really see is the dot superimposed on your target – just like it should be.

Green dot is the optic, red dot is the front sight.

The size of the optic lens is a non-issue when shooting… but it might be an issue when you draw and line up your pistol.

I’ve been shooting red dot pistols for years now, and I would absolutely say that my time and rounds spent shooting red dots are probably at least 10 times that of what I’ve put into irons. I am very confident in my draw and presentation and pretty rarely miss having my dot be where I want it.

For me, I did not see any difference between the Kraken and a normal red dot. But I could see how people that are newer to the platform having a bit more trouble finding their dot because of the smaller window.

The solution to that is more training, but that’s a solution for everything, more or less.

One downside I did feel due to the window size was a slightly diminished ability to track my dot through recoil. This is kind of an advanced topic for shooting with red dots but one of the major benefits of a dot is that you don’t entirely have to wait for it to settle. As long as the dot is on the target, you can send the shot. 

With a larger window, it’s easier to track the dot through recoil. Practically speaking, the slightly smaller window didn’t really impact my shot times or cadence enough to matter, but it did feel different. This is just one of the tradeoffs you get with an enclosed emitter. 


I’ve EDC carried the Kraken on my Glock for a few months now, I’ve run at least 2,000 rounds through the gun in that time, and I’ve banged it around a lot during travel and training. I’ve even dropped it multiple times just to see how it faired.

The Kraken has come through with flying colors. No issues at all. The dot is perfect, the glass is clear, the housing is very strong.

While I haven’t smashed it with a hammer or anything crazy, I have no doubt that the Kraken can stand up to real-life use. 

I won’t keep you waiting, I strongly recommend the Kraken and the Wolverine.

As much as I really like the Kraken, I don’t think it is going to be for everyone. While having a closed emitter is really nice, the Kraken is a beefy optic that takes up some room. On a compact pistol, this is not going to be everyone’s cup of tea, but on larger format applications like ARs, offset mounts, or even just larger pistols like a Glock 17 or Glock 34, the Kraken will feel and look right at home.

Personally, I’m going to keep it as my EDC on this Glock 19 for the time being. I like it, I like the durability it offers, and I like how super bright the green dot is.

I’m a big believer in offset red dots for things like ARs, and I already know that I want a second Kraken for my 6mm ARC rifle.


Some parting words of advice I’ll leave with you is that while the Kraken is an MRDS it is different from the normal Trijicon RMR or Holosun MRDS you might be used to. Closed emitter takes a little getting used to. Not as much as going from irons to MRDS, but more than going from standard iron sights to night sights.

Give yourself a couple of range sessions to settle in with the Kraken before you decide if it is right for you.

The more I used it, the more I liked it.

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