Many of you may be familiar with the H&K USP but did you know it has a bigger sibling and they were developed at the same time? In the early 1990s US SOCOM needed a new service pistol. They held the Offensive Handgun Weapon System trials. Only Colt and H&K participated. The Colt OHWS failed the trials which let the door wide open for H&K to submit their entry the MK23MOD0. It won the contract and H&K makes a civilian version called the MARK23.

MK23 Mod 0 Background

The OHWS program wanted a primary offensive handgun. Yes they wanted a handgun to be their primary weapon. One of the reasons the Colt OHWS failed was due to the fact that it could not shoot high pressure ammo like .45 Super or +P .45 acp. Another reason the Colt failed was due to utilizing a suppressor. The Colt pistol used a muzzle brake which made suppressing the Colt more complicated.

 

 

You can see what the OHWS program required just by looking at the photos above of the failed Colt OHWS. SOCOM wanted a handgun that is suppressed and uses a Laser Aiming Module (LAM).

H&K made the MK23 while Knight’s Armament won the contract to supply the MK23 with their suppressor. H&K did submit an eccentric box shaped suppressor but the KAC was chosen over it so only the prototype exists.

In the photo below you can see the cylindrical KAC suppressor and below that is the square H&K Phase 1 suppressor.

 

Just like the Colt OHWS, the MK23 also used a LAM. Both Insight and Wilcox developed laser aiming modules for the MK23. In the photo above you can see some variations. The bottom MK23 says US GOVT engraved on the slide while the top MK23 has “USSOCOM” engraved. The LAMs are both made by Insight. The big boxy one is a prototype and Insight scrapped that design for a more streamlined setup which you can see below.

Wilcox designed their own LAM unit which was completely modular and ahead of its time.

The Wilcox unit was called the Nightstalker. It consisted of three parts. A mount with paddle switch which sits below the trigger guard, the light unit at the bottom and a laser unit in the middle. You can remove the light and just use the laser or remove the laser for just the light. Both the light and laser have visible and IR spectrum modes. The second generation Nightstalker laser incorporated an LCD display at the bottom so you know what mode you are in. You can change the pulse and brightness of the laser. You can also dim the flashlight bulb as well to control the amount of light.

Below are photos by Chris aka yz125racer on HKPro forums. He acquired a Nightstalker light and laser and shared these photos with me.

MK23 Fanaticism

Most people collect the H&K MARK23 for one of two reasons. One is its history in US SOCOM which was issued to Special Forces. The other reason is the 1998 hit video game, Konami’s Metal Gear Solid for the Playstation.

You may think liking a handgun because it was so prominently showcased in a video game is silly. Well I debate that with the fact that hardly anyone who has a MARK23 was issued one. So it is all a form of hero worship. Guns can be fun and enjoyed for many reasons. Metal Gear Solid is one of the all time greatest video games and has a lot of gun porn in it. It caused a lot of boys in the 90’s to like guns and eventually buy real versions of said guns. How is that any different than people who collect guns from wars/battles they had no part in let alone were not even alive for?

Metal Gear Solid is cool and the MK23 is even cooler.

I started collecting airsoft MK23s back in the early 2000s. One is a simple spring action pistol, the second one from the bottom is a non-blow back version (NBB). Both were made by Tokyo Marui. The second from the top is the gas blow back version by KSC. The Tokyo Marui NBB came equipped with a faux suppressor and insight prototype style LAM unit. The LAM used three AAA alkaline batteries and just had a white and red LED. It wasn’t very bright and it did not have a laser. Later another airsoft company came out with their own LAM that uses Surefire bulbs and has a red laser built inside. It is the Wolf M97 you see on the real MARK23 below.

To put things into perspective, the real insight LAM AN/PEQ6 LM450 can fetch for more than a Mark23 and KAC suppressor combined. That is for a surplus issued LAM unit.The Wilcox unit is semi rare since it was made in far fewer numbers and can fetch north of $3,000. That is a bit much for an antiquated and obsolete LAM from the 1990s. However availability and demand are constantly in cahoots which drives the price more than the Insight.

Deceptively Large

The MK23 does not seem that large when you see photos of it. But once you see it in person your perceptions will change. The MARK23 is about as big as a Desert Eagle. Below you can see how it is almost as big as my Omega MP5K.

You can see how much bigger the MARK23 is compared to my FNX-45 Tactical.

Variant MARK23s

So the MK23 and MARK23 have different engravings. Besides the difference between the US SOCOM MK23 Mod 0 and the civilian version MARK23, there are variations even in the civilian releases.

I met up with a a fellow MARK23 owner and he has an AE date code MARK23. The slide has a glossy finish which wears a little too easily. The serial numbers on the barrel are engraved differently as well.

Suppressing The MARK23

Since the MK23 was issued with a KAC suppressor, I reached out to my FFL friends if they had a KAC suppressor for a MARK23. My friend at Cory of CDS Arms transferred a KAC can for his customer Minh, and got me in contact with him. Minh was kind enough to meet up and we compared our MARK23s. I compared his KAC suppressor against my Osprey 45. The MARK23 has a unique thread pitch. It is Metric 16×1 RH where as the subsequent H&K pistols in .45acp are threaded 16×1 LH. I had to order a 16×1 RH piston from Silencer Co to put my Osprey 45 on the MARK23.

Minh brought along his HK pistol collection as well as his Rugged Obsidian 45 can. Look how much bigger the MARK23 is compared to the USP Tactical below it.

The MARK23 sounds similar when shot with the KAC and Osprey45 however the KAC is a smidgen louder. I shot both side by side and noticed my ear felt slightly uncomfortable with the KAC. Not bad for a suppressor designed in the mid 1990s. We also poured water in both the Osprey 45 and KAC suppressor. Minh warned me about the KAC. Sure enough, there was a considerable amount of water and carbon flying back when shooting the MARK23 with a wet KAC.  My safety glasses were completely covered from the KAC. The Osprey did not spit any water back in my face.

Another consideration is that my Osprey45 has a wrap around the body of the can. So my friend Corey met up with me and brought his stock Osprey45 to compare and I compared the MK23 to my FNX45 tactical.

 

The Osprey45 aesthetic design flows surprisingly well with the MARK23. It is almost as if it was designed for it. I found out that the SilencerCo Osprey 45 was designed around Mike Pappas’ USP Tactical. Here is a quote from Mike Pappas regarding the design of the Osprey 45.

HK Tactical to be specific. The actual pistol used by SilencerCo is a personal pistol of mine. We mimicked the slide serrations from that firearm onto the Osprey. Does this make my pistol worth anything? Hahahahaha. The bulk of the sound testing and development was done using this host.

MARK23 Accessories

When the MARK23 was released, it came bundled with a bunch of extra accessories. One of which was a faux KAC suppressor. Thanks to Chris for sharing this photo.

 

The MARK23s came with an Eagle Industries pistol case. They came in Black, OD green and a limited run of woodland camo.

The FNX-45 Tactical pistol case is actually the same case as the MARK23. Unfortunately the MARK23 no longer come with these cases. This one came in a standard plastic H&K pistol box. I happened to have a spare FNX-45 case that I purchased a few years ago before I bought my FNX-45 tactical. I bought it to house my Glock 21/41 pistols.

The MARK23 has a proprietary accessory rail however you can get a rail adapter to attach modern weapon lights and lasers. I ordered one from GG&G and I can mount my SureFire weapon lights to the MARK23.

The MARK23 came with two 10 round magazines but there are higher capacity magazines available. There is a factory 12 round mag and Promag makes a 20 rounder.

Final Thoughts

The MARK23 is an obsolete handgun. There are other handguns like the FNX-45 Tactical that out perform it. 12 rounds of .45 acp isn’t bad, but my Glock 21 holds 13 rounds in the magazine and the FNX-45 holds 15 rounds. While the MARK23 was ahead of its time with abidextrous safety selectors, it is not a big deal anymore. It does have a decocking lever but I hardly use it.

However since when do guns need to be practical? While the large size makes it impractical for concealed carry and it is not red dot ready, the MARK23 is so much fun to shoot suppressed with a LAM unit. I was pleasantly surprised how easy it is to hit targets at distance with the factory iron sights out to 50 yards. My only complaint would be the price. The MARK23 is not a cheap gun. Retail is just above $2,000. That is a bit much for a .45 acp handgun. However this is a bucket list firearm for me. I remember seeing one in a local gun store when I was a firearm noob. I did not have much money and saw a used MARK23 for $1,200. At the time I had no frame of reference. Ignorantly I thought that was expensive. How wrong I was. I kick myself for not buying it back then. I also came across a limited edition Tan polymer MARK23 at a gun show a couple years later. I believe H&K only made 500 of these. I regret not buying it right then and there too.

The MARK23 is just cool and definitely something you should get if you are an H&K fan or a Metal Gear Solid fan.