Kahr Arms has made quite a reputation for itself in the few years it has been producing its innovative little concealed carry pistols. They are remarkably accurate and reliable with factory ammo, though occasionally they’ll throw their first hand-chambered shot to a slightly different point-of-aim than the mechanically cycled follow-up shots. Seasoned shooters trying them for the first time invariably remark on the smoothness of the Kahr’s DAO trigger stroke.

Now Kahr has introduced its smallest gun yet, the Micro Kahr. It holds five .40 S&W rounds in its magazine and a sixth, safely, in its firing chamber. Yet the Micro Kahr MK40 is only 5.35″ long with its 3.09″ barrel, 4.55″ high from butt to top of holstered gun, and measures only 0.94″ wide. It weighs 23.1 ozs. unloaded, which is only .1 oz. more than the pistol that has been the definitive .380 pocket automatic since the 1930s, the Walther PPK.


Smallest Of The Small
These Kahr MK40 pistols are small and slim. The first Kahr was the K9, a compact pistol that held 7+1 rounds of 9mm. It was followed by its near twin, the K40, which held 6+1 rounds of .40 S&W. Next came their first “Micro” Kahr, the MK9, a tiny 9mm that held seven rounds total, shortened at both butt and muzzle.

Attempts to make a similar size reduction on the .40 proved frustrating. The slide velocity of the much more powerful .40 S&W cartridge was difficult to stabilize on anything smaller than the already compact K40 slide. Kahr chose a compromise route, the K40 Covert, which mated a regular (compact) K40 barrel slide assembly with the short (subcompact) grip frame of the MK9. It proved to be a nice little gun. Still, the market clamored for a .40 as small overall as Kahr’s Micro 9mm.

Research continued, and the MK40 Micro was at last ready for shipment by summer of 1999. What got them over the hump was a couple of engineering tweaks: increasing the mass of the slide, and installing the captive double-spring recoil spring design pioneered by Seecamp. Kahr Arms negotiated with Seecamp and paid for the right to use the patented recoil spring system in their guns.

You’ll find that about 1 oz. has been added to the slide of the MK40, and that it’s a whisker higher at the rear, with more mass at the area at the back of the slide of this striker-fired pistol. This part of such a gun is commonly called the “slide cover.” It doesn’t change the dimensions enough to interfere with holstering.

I found this pistol would adapt nicely to other Kahr holsters from Alessi, DeSantis and Mitch Rosen. Because of its rounded edges at front and back, it also fits very nicely in elastic bellybands, a natural home for self-defense pistols of this size and shape.

The engineering tweaks were done by Justin Moon, the prime mover at Kahr Arms who came up with the basic pistol design. Would they make a gun this small work with powerful .40 S&W ammo? I took it to the range to find out.

Kahr MK40

Cor-Bon 165 gr. JHP +P

American Eagle180 gr. FMJ

Winchester SXT 180 gr. JHP

Black Hills 155 gr. JHP

ProLoad Tactical 135 gr. JHP

CCI Blazer 180 gr. PHP


Right, a sharp edge on the underside of the slide lock lever proved to be a hindrance in standard shooting.

Popular Pistol

Everybody on the range wanted to shoot this little gun. Some brought their own ammo. I lost count of how many times the MK40 was discharged, and can only guess it to be somewhere short of 1,000 rounds. I did, however, keep count of malfunctions.

There were only four, none of which I can really blame on the pistol, at least not entirely. Two occurred during accuracy testing. The last spent casing from a string of five was jammed in the ejection port while testing the Cor-Bon 165 gr. hollowpoint.

As it says on the T-shirt the ammo manufacturer offers, “Cor-Bon Is Hot Stuff!” The 165 gr. JHP has a nominal velocity of 1,125 fps. Cor-Bon advertises it as “+P” ammo. Now, SAAMI has set no industry specifications for a “+P” power level in .40 S&W, but if they do, Cor-Bon will define what it is.

Remember, the .40 S&W cartridge is a bigbore round designed to work in the envelope of a pistol designed for the generally less powerful 9mm. Firing .40 S&W causes slides to run faster than 9mm. Get into +P .40, and the slides run faster yet.

This is no problem in a big service pistol. One year, Taurus provided .40 caliber pistols and Cor-Bon provided the ammo for a side match at Second Chance. The Taurus guns worked like champs; the Cor-Bon .40 ammo blew the heavy bowling pins off the tables as if they’d been smacked with .45 slugs and all was well with the universe.

But the Taurus .40 is a big pistol, bigger than many .45s. The Kahr MK40 is smaller than some .380s. I think the hot load was just running the slide too fast for the cyclic rate to keep up.

Aggressive Testing

The second malfunction also occurred in the accuracy testing stage, a feedway stoppage with a CCI Blazer 180 gr. plated hollowpoint. In a tradition begun long ago with their “flying ashtray” .45 bullets, CCI produces a very “aggressive” hollowpoint projectile with a very wide mouth. Unless you have straight-line feed or a gun especially designed for such a bullet, it can hang up on the way in. We only had one such malfunction with the Kahr, however.

The other two malfunctions occurred when I was shooting a qualification course, and I reflexively cleared them. These were failures for the slide to go into battery, that is, to carry the fresh round all the way into the firing chamber. I realized as they happened, on the 10 yard line, that I was focusing so much on sight alignment and trigger control that I had forgotten to lock my wrists. This is a “shooter error” thing.

So long as the grip was firm and the wrists were locked, everything else went through the gun cleanly. In my hands, and in the hands of others.

A Nuprin Moment
You expect very small, very powerful guns to kick hard enough to hurt you. This one did, and it didn’t. It was a matter of grasp.

Properly held, the pistol snapped instantly back on target. You knew you were shooting something very potent, but it didn’t hurt if you grasped it correctly. I felt the torque of the recoil more in the wrists than in the hands.

I might not recommend it as the gun of choice for the arthritic, but the fact is that I am arthritic, and there was no lingering discomfort after a long shooting session. In the immortal words of the first world champion of the combat pistol, Ray Chapman, “It stops hurting as soon as you stop shooting.”

Frankly, it doesn’t really hurt when you’re shooting. That is, unless you use an improper grasp, and because of that, I want to reach for an engineer’s steel ruler and smack somebody at Kahr Arms across the knuckles.

The problem is, this particular gun comes out of the box with a sharp edge on the bottom rear of the slide stop lever. If you take a normal grasp on the pistol with your right hand, this sharp edge will nail you somewhere on your right thumb. I shot it left-handed and it was no problem. Right-handed, I had to transition to John Farnam’s signature grasp with both thumbs pointed up to the sky.

This grasp works for Farnam and many of his students. It doesn’t work for me in terms of maximum performance, but in this shooting test, Farnam’s high-thumb grasp kept me from lacerating my thumbs on that sharp-edged slide stop lever.

Note to Justin Moon and the rest of the Kahr design team: Round off the edge on the MK40’s slide lock lever!

Unexpectedly Easy
The smoothness of the DAO trigger stroke, and the fortuitous similarity of the grip shape and angle to that of the Browning Hi-Power, made this gun easier to shoot than you would expect with a subcompact .40 caliber pocket gun.

I’ve seen DAO pistols in this power range whose triggers were so bad, you couldn’t stabilize the gun to assess its mechanical accuracy unless you had a machine rest. In such a case, the resulting data is meaningless unless you have a robot bodyguard to fire the pistol for you.

Testing was done at 25 yards with the pistol held in both hands and rested on a bench, the equivalent of firing over an auto hood or a wall. Five-shot groups were test-fired with half a dozen commercial loads encompassing the four most common bullet weights in caliber .40 S&W.

Most shooters expect to actually deploy a self-defense pistol at seven yards or less, within which distance the MK40 will stay on the deep brain area of a human anatomy target all day long if you do your part. Accuracy, in a combat pistol, is a relative thing.

That said, you do like to know your pistol can hit what you aim at if Destiny brings you to something like the North Hollywood Bank Robbery Shootout, where long-range pistol shots were required to stop innocent people from being hurt.

Note that with four of the tested cartridges, all five shots went into less than 3″ and with one cartridge, all five went into less than 2″.

This is ample accuracy for self defense purposes. It is, in fact, damn good accuracy from a pistol this small and this powerful.
The Kahr On The Street
The MK40 is a personal defense weapon. You may find yourself putting it on when you get dressed and not taking it off until you undress for bed. Once I knew it would work and loaded it with Pro-Load Tactical 135 gr. hollowpoints, I wore it daily as either primary gun in a hot and humid summer, or as backup in my left side pocket.

In a Bianchi Ranger elastic bellyband under a tucked-in shirt, worn butt-forward just to the left of the navel, I found it extremely comfortable. That sharp edge on the slide lock lever only becomes palpable when it hits your thumb in firing, not when you wear it next to your bare belly, walking around doing your daily chores.

In a DeSantis IWB holster, it was extremely concealable and comfortable. There was just enough weight to reassure me that it was there. Though only two fingers can get on the grip-frame at once, it was surprisingly quick to draw in the qualification shoot. Re-holstering was smooth and clean, and comfort was a hair away from “you don’t really have a holstered pistol in your waistband.”

The third holster was a leather pocket rig put together by Charlie Hancock, president of Charlie Company, who came up with a helluva neat little rig. It holds the little auto pistol in just the right position for a straight-up draw out of the pocket, with a forward lip to catch the scabbard in the pocket lining and hang on to it while the pistol escapes. Since I carry guns this size mainly for backup, this was the handiest of all the holsters tested in terms of my personal needs.
Shooting Under Pressure
I used the MK40 to shoot an off duty/backup gun qualification course that’s on the approved list issued by the Police Standards and Training Council of the state where I live. I drew from the DeSantis IWB holster. Sixty shots were fired, at ranges from four to 15 yards, including strong-hand and weak-hand-only.

I began each stage with a round in the chamber and the five-shot magazine in place, for six shots total. This particular course allows for five-shot J-frame revolvers, with a 188 (75 percent) of 250 possible points considered passing, or 225 out of 300 points if you shoot a six-shot pistol. Carried with a round in the chamber, the MK40 is a six-shot pistol, so I went the latter route.

The 5+1 were in the MK40 to start, in the DeSantis holster hidden beneath an untucked and slightly oversize golf shirt. I put the first spare magazine, the extended one that comes with the gun with a plastic bottom plate designed to keep it from over-travelling, in an LFI Concealment Rig magazine pouch for a single stack magazine, inside my waistband on the left.

A regular K-40 magazine was in my left hip pocket for the occasionally required second reload for a third gunload within the time frames required. The magazines were loaded with a mix of ammo.

At the four yard line, weak-hand-only, the Kahr delivered six shots into about 3″ in well under the eight-second time specified in the course of fire. Right-hand-only stayed in the same group. So did the 12 shots with the reload from 7 yards.

At 10 yards, I relaxed the grip and had two failures to return to battery. The relaxed grip probably accounted for the group opening at that point, too, though everything was still in the center “five-point” zone of the IPSC target.

At 15 yards, one shot went way east, almost 1″ into the four-point zone. I was trying to shoot with my thumbs straight up, and didn’t have as secure a hold as I have with techniques I practice more regularly. That’s a cheap excuse, of course: you adapt the hold to the pistol.

I was trying to avoid that damn sharp edge on the slide stop lever, and I paid the price with a total score of 299 out of 300. Now, I’m damn glad to take a 99.66 percent, but when we train with the weapons we’ll be using to defend ourselves against death, we always look for 100 percent.

Grit And Pocket Lint
It works in the pocket. Kahrs work on the ankle — one of the few auto pistol designs that will function reliably after being exposed to the grit that is kicked up constantly by the shoes that are inches below the holstered pistol. The Mini-Glocks and the Kel-Tec 9mm are in this elite category with the Kahr.

This smallest of .40s is an important gun. It opens a new dimension in deep concealment with large bore power. It is controllable and it works.

More gun Reviews: guncritic

Leave a Reply

Your email address will not be published. Required fields are marked *