Review: Korth Mongoose Revolver

Korth Mongoose: The Most Interesting Revolver in the World

posted on January 26, 2022
Korth Mongoose revolver

In the minds of many, Germany is synonymous with “precision craftsmanship.” One only need look at the list of German car manufacturers: Porsche, Audi, BMW and Mercedes-Benz [also VW, but we’ll forget about them for now]. But, it’s not just cars, because Germany also manufactures incredibly high-end razor blades, the country is the home of Leica cameras and, of course, Germany manufactures some of the finest firearms on earth. Companies like Walther, Heckler & Koch and Blaser are all well-known among firearm enthusiasts in the United States.

But, there’s a German company making one of the nicest guns out there, and there’s a good chance you’ve never heard of it. That company is Korth, and it makes revolvers. Nighthawk Custom, the famed 1911 shop, imports those revolvers. One of those revolvers is called the Mongoose, and on the surface, it looks almost basic.

In some ways, the Mongoose is basic. It’s the most affordable revolver in the Korth lineup that Nighthawk currently imports—and if you think $3,700 is affordable, my congratulations. It’s a straightforward, six-shot, double-action revolver with adjustable sights and a number of barrel lengths are available. This sample provided had a 3-inch barrel, yet still had the adjustable rear sights paired with a black, ramped front sight. The finish is also black, which along with the black rubber grips have the effect of making this Mongoose look like Darth Vader’s snubby. The only things that break up the black-on-black-on-black appearance are the logos, the silver trigger and hammer and a little silver button where a Smith & Wesson would have the cylinder-retention screw.

Korth Features
The Mongoose is available with a cylinder for 9 mm ammunition that does not require the use of moonclips to extract the cases • While providing adequate purchase, the author felt the Hogue rubber grips were a touch declasse for such a high-end revolver • The adjustable rear sight pairs nicely with the thick, serrated ramp at the front • Swapping cylinders is simple and is performed by pressing the silver button on the frame • The knurled, exposed hammer breaks up the largely black-on-black monotony of the Mongoose’s appearance • Fit and finish on this revolver are unsurprisingly exquisite, with tight tolerances and supreme reliability combining to create a mechanical masterpiece.

Let’s talk about that little silver button, because it’s part of the Mongoose’s cool party trick: interchangeable cylinders that can be swapped in and out without tools. Simply open the cylinder, press the silver button and pull the cylinder off. Reverse those steps to install a new cylinder. The .357 Mag. cylinder works like any other revolver cylinder, but the 9 mm cylinder is different. Most revolvers that can fire rimless cartridges require the shooter to use half- or full-moon clips to properly headspace the rounds for ignition and extraction. The Korth Mongoose, on the other hand, does not. Instead, the extractor star has a small, spring-loaded clip that pops out to retain the 9 mm rounds for firing and extraction.

The ability to fire 9 mm without moon clips is definitely the Mongoose’s coolest party trick, but it’s not the only one this wheelgun offers. Technically, referring to sights as a trick is probably not correct, but the rear adjustable sight on the Mongoose is so svelte that at first glance, it appeared to be a fixed sight. That first glance turned out incorrect, and the rear is fully adjustable for windage and elevation. This is a good thing, since in testing, 9 mm rounds had an extremely low point-of-impact compared to .38 Spl. and .357 Mag. rounds.

By now, you’re probably like “Yeah, yeah, yeah. All that is great, but how is it to shoot the thing?” So glad you asked. The two most critical factors to comfort and speed when shooting a revolver are the shape of the grips and the trigger pull/reset. Because this Mongoose has a 3-inch barrel, it came with a Hogue grip that has small finger grooves and does not fully enclose the backstrap. That hurts the gun in two areas: First, it decreases the available surface-contact area on the grip, which makes it harder to get a positive firing grip. Secondly, the exposed backstrap imparts more felt recoil to the shooter’s hand, which was immediately evident when the first round of .357 Mag. went off. It’s mildly annoying that a $3,700 revolver comes from the factory with a $10 Hogue rubber grip on it. Thankfully, there are other grip options available from Nighthawk, but there isn’t a huge aftermarket for Korth grips, and existing grips for Rugers or Smith & Wessons of similar frame sizes won’t fit the Mongoose.

Korth Mongoose features
Opening to the left, the cylinder is finely machined and can accept certain extant speedloaders • Located beneath the hammer, the cylinder-release latch is easy to actuate, yet unobtrusive • Fine fit and finish extend to the plunger channel inset into the frame • Perhaps the Korth Mongoose’s most exemplary feature is its outstanding trigger.

However, as bad as the grip is, the trigger pull makes up for that in spades. Using a Lyman digital trigger-pull gauge, the double-action pull was measured three times and the average reported. The same method was used to measure the single-action (SA) trigger. The results: a double-action (DA) trigger pull that averaged 7 pounds, 9.6 ounces and an SA pull of 2 pounds, 2.3 ounces. But even better, the reset on the DA pull is fast and positive. This is critical for speed shooting, because the gun needs springs that will rapidly drive the trigger forward so the gun can be ready to fire again.

Often, to get a light DA trigger pull, the recoil/rebound spring will be lightened, which can affect how quickly the trigger resets. Most often this will occur with kitchen-table revolver-action jobs, and actually makes the gun slower to shoot. That’s not the case with the Korth Mongoose. To see how well the gun shoots at speed, the rapid-fire test was used. This is simple: shoot three strings of six shots each from the low ready. The goal for each string is to be less than 2.000 seconds and to get consistent splits around .25 second per shot. The Mongoose recorded times of 1.86, 1.93, and 1.88. Splits were consistently in the .23 to .26 range, which means that the trigger is 1) easy to pull to the rear, and 2) resets quickly.

Korth Mongoose specs

A good trigger also aids accuracy. Since the key to accuracy is “pull the trigger in such a way that it doesn’t disturb your sights,” having a smooth trigger pull means you’re less likely to yoink the gun off target [of course, a proper grip will render this less of a problem]. As established, the trigger on the Mongoose is great. Instead of following the protocol for 3-inch-barreled guns and shooting groups at close range, the Mongoose got pushed to 20 yards. Groups were shot single-action off a rest to maximize accuracy. Two 9 mm loads, two .38 Spl. loads and one .357 Mag. load were selected to test the Mongoose. The best performer of the day was the 125-grain SJHP .38 Spl. +P from Remington, which turned in a sub-1-inch best group and an average group size of 1.37 inches. Unsurprisingly, the worst group was one of the 9 mm rounds, Hornady’s Critical Defense 115-grain round. This had a largest group size of 5 inches and an average group size of 4.43 inches. This shouldn’t be construed as a knock on Hornady’s 9 mm though; when tested in semi-automatic pistols, that round has proven to be incredibly accurate.

…The Mongoose’s cool party trick: interchangeable cylinders that can be swapped in and out without tools. Simply open the cylinder, press the silver button and pull the cylinder off. Reverse those steps to install a new cylinder.

It does illustrate why shooting 9 mm out of guns designed for .357 Mag. can be a frustrating exercise. The semi-auto round’s projectile is slightly smaller, so it’s like pitching a 9 mm Tic-Tac down a .357 Mag. hallway. It doesn’t engage the rifling as well as a .38 Spl. or .357 Mag. round does, making it less accurate. Plus, even with the correct cylinder, the 9 mm round will still have to jump a tremendous amount of freebore before it makes contact with the forcing cone. If you’re not a revolver aficionado, freebore is the amount of distance the projectile has to travel in the cylinder before engaging the forcing cone on a revolver. It becomes a problem in “conversion” revolvers because the forcing-cone length is set, and the cylinder needs to correctly space off the forcing cone for the gun to work. That’s why purpose-built 9 mm revolvers like the Ruger Super GP100 and Smith & Wesson 929 have these weird looking, long forcing cones that protrude deeper into the cylinder window to meet up with the stubby little cylinder. It should be noted that an average 4-ish-inch group at 20 yards is still pretty darn good for a 3-inch gun, and likely exceeds the ability of the average shooter, so don’t be too worried when shooting 9 mm through the Korth.

There were no issues with .38 Spl. or .357 Mag. ammo. The other .38 Spl. load also delivered sub-2-inch groups, and the .357 Mag. shot a hair larger than 2.5 inches. Really, the only thing impeding accuracy with the Mongoose is the fat, ramped front sight. Sure, the Mongoose is the “entry-level” Korth, but for almost four grand, a fiber-optic pipe or brass-bead sight would be nice. The front sight is so “thicc” it should be in a hip-hop video, and it fills up most of the rear-sight gap, leaving little light for contrast.

But really, these are extremely minor quibbles. The grip isn’t perfect and it doesn’t shoot tiny little groups with ammo it’s not really designed to shoot and, oh, the sights could be a little better? Those aren’t real complaints. Plus, Korth used a cylinder pattern that lets you use existing GP100/L-Frame six-shot speedloaders, and the 3-inch gun fits some holsters for those guns. The Mongoose was tested in a Galco Combat Master, a Galco Summer Comfort, a Blade-Tech OWB competition holster and a JM Custom Kydex AIWB holster. It fit all with no issues, although it was a little tight getting it out of the Blade-Tech holster.

Of course, the question that comes at the end of every review of a high-dollar gun like this is always “is it worth the price tag?” But, that’s kind of a ridiculous question, isn’t it? If someone wants a Porsche, you don’t ask if it was worth the price, you just say “nice Porsche, man.” The Korth Mongoose is a lot like that. You don’t buy a Mongoose because you’re going to drag it through the mud at an IDPA match; you buy one because you want to own a Korth. Is the gun itself a fantastic machine and probably the nicest production revolver on the planet? Yes. And if you’re the kind of person who thinks that’s cool, then of course it’s worth it. If you’re not, it’s still worth it, it just isn’t for you.

Korth Mongoose

Korth Mongoose specs


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