Good afternoon everyone and welcome back to TFB’s Silencer Saturday brought to you by Yankee Hill Machine, manufacturers of the YHM R9 multi-caliber suppressor. Last week we knit-picked our own James Reeves on his faulty rifle suppressor caliber analysis. This week we take a look at what is probably the most famous firearm/suppressor combination ever built: the Heckler & Koch MARK 23 (MK 23) pistol and Knight’s Armament MK23 suppressor. Let’s take a look at why the H&K and KAC MK23 setup is a must-have for silencer fans.
With all of the history and legend that surrounds the USSOCOM MK23 (the official designation for the complete pistol/aiming device/suppressor kit), there’s not much that hasn’t been discussed ad nauseam. Most recently, our own Nick C. fulfilled own of his life goals of reviewing the MK23, complete with laser beams and silencers. And Austin just partnered up with the 1911 Syndicate for a very cool video. I’ve included links to both reviews, the MK23 wiki page, videos, and other references for you to peruse at your leisure.
Not being a huge Metal Gear Solid fan (I played, poorly), a local H&K pistol club chapter president (those membership fees) or even a fan of the .45 ACP cartridge itself (9mm is the one true pistol king), I never gave the H&K MARK 23 much thought. Until recently. As we fast approach the 200th episode of Silencer Saturday, I decided that ownership of the H&K and KAC MK23 package is a requirement. And I haven’t been this excited about a new gun and suppressor in a long time.
Both the MARK 23 pistol and KAC MK23 suppressor are in very limited supply and are not “stocking-dealer” type items. The pistol took about six months to immigrate to the U.S. from Germany and I paid over MSRP for the suppressor to avoid a 9-12 month manufacturing window estimate. If there are first-world problems, these are the “my Lambo’s interior doesn’t match the exterior of my summer house” firearm equivalents.
MK23 @ TFB
I’ve used the term end-of-the-world capable as a descriptor in the past, but the H&K and KAC MK23 is really the pinnacle of strength and resilience. Match grade out of the box and capable of insane firing schedules, the MK23 sets the standard by which other pistols and suppressors can only dream to achieve.
H&K MK23 Development/Testing
During testing, MK 23 pistols met the most stringent operational and accuracy requirements ever demanded of a combat handgun. MK 23 pistols achieved match grade accuracy of less than a 2.5-inch maximum extreme spread in 5-round shot groups at 25 meters with service ammunition. Endurance testing demonstrated a service life of over 30,000 rounds of +P ammunition with no parts breakage, with an additional 30,000 rounds certified on the slide and frame.
To meet the reliability requirement, the pistol had to demonstrate a minimum of 2,000 mean rounds between stoppages (MRBS) with both M1911 ball and +P ammunition. The minimum MRBS achieved in testing was 6,027 and the maximum was 15,122. Out of over 450 accuracy test firings from a precision firing fixture, MK 23 pistols far exceeded the government requirement, averaging 1.44 inches with 65 groups of less than one inch. There were four groups of .5 inches with 5 rounds going through the same hole! This included firing with and without the sound/flash suppressor attached.
Three pistols were tested for accuracy after firing over 30,000 rounds, the specified service life of the pistol, and still met the new pistol accuracy requirement. An innovative design feature, a high temperature rubber O-ring on the barrel that seals the barrel in the slide until unlocking, led to this remarkable achievement. The O-ring lasts beyond 20,000 rounds and can be replaced by the operator without tools in seconds. To meet operational environmental requirements, the pistol was function tested at +140 and -250 F, immersed in salt water, exposed to surf, salt-fog, sand-dust, mud, unlubricated and
a variety of other fouled environments. A special maritime surface coating protects the pistol from corrosion in all of these operational environments.
If you are asking why anyone that would need a pistol and suppressor that perform at these levels, you’re asking the wrong questions. This firearm and suppressor setup is a piece of history that deserves to be recognized for its design and engineering accomplishments. Plus, it’s cool as hell.
SILENCER SATURDAY #178: H&K And KAC MK23 – The Most Famous Suppressor Combo?
The only firearm/suppressor combinations that come close to being as recognizable is the H&K MP5SD, the MK12 SPR with the Allen Engineering AEM5, the MAC 10 with a Sionics suppressor and maybe the Beretta pistol with slide lock an the KAC Hush Puppy. The KAC MK23 dimples that are also found on some of their other suppressors like the KAC MP5 and MP5SD are this can’s dead giveaway. Whether the H&K MK23 with KAC suppressor found its way into movies, TV shows and video games because of its technical prowess or it’s recognizable form factor is unknown. But I’d wager Hollywood helped sell more MK23 pistols than any SOCOM operator.
One of my favorite mottos most certainly applies to the MK23 – There Is No Free Lunch. If you want match-grade accuracy, multi-conflict reliability, and bomb-proof construction, it will come at a cost. Weighing in at 3.5 pounds unloaded and measuring to about a foot and a half in total length, the MK23 is a beast of a system. No one besides SHAQ appendix carries the H&K MK23. And at $2,500 for the pistol and ~$1,500 for the suppressor, the package is pricey before adding light/laser, ammo, holster and other related gear.
The Mark 23 provides this accuracy without the need for hand-fitted parts common in custom-built match pistols costing thousands of dollars more. One of the most thoroughly tested handguns in history, the MK23/Mark 23 project originated in 1991 when HK began development for the U.S. Special Operations Command, the organization that directs the activities of America’s most elite military units, including the Navy SEALs and the Army Special Forces. On May 1, 1996, the first HK MK 23 pistols were delivered to the U.S. Special Operations Command for operational deployment, making the MK 23 the first caliber .45 ACP pistol to enter American military service since the venerable Government Model 1911A1. During testing, MK 23 pistols met the most stringent operational and accuracy requirements ever demanded of a combat handgun. Endurance testing demonstrated a service life of over 30,000 rounds of +P ammunition. To meet the reliability requirement, the pistol had to demonstrate a minimum of 2,000 mean rounds between stoppages (MRBS) with both M1911 ball and +P ammunition. All pistols exceeded the 2000 MRBS with an average of 6000 MRBS. In more than 450 accuracy test firings from a precision firing fixture at 25 meters, MK 23 pistols far exceeded the government requirement, averaging 1.44 inches, with 65 groups of less than one inch. There were four groups of .5 inches, with 5 rounds going through the same hole!
- M16x1 RH Threaded O-ring barrel with polygonal bore profile
- Match grade trigger
- One piece machined steel slide
- Frame mounted decocking lever and separate ambidextrous safety lever
- Can be carried “cocked and locked” in single action mode with the safety lever on
- Patented HK recoil reduction system
- Corrosion resistant blued finish
- Corrosion proof fiber-reinforced polymer frame
- Oversized trigger guard for use with gloves
- Universal mounting grooves for installing accessories
- Ambidextrous magazine release lever
- Extended slide release
- Extractor doubles as a loaded chamber indicator
- Patented Lock-Out Safety device
- UPC: 642230261587
- Caliber: .45 AUTO
- Overall Length: 9.65 in.
- Height: 5.90 in.
- Width: 1.53 in.
- Barrel Length: 5.87 in.
- Sight Radius: 7.76 in.
- Weight: 39.36 oz
- Single Action Trigger Pull: 5.17 lb
- Double Action Trigger Pull: 11.47 lb
- MSRP: $2,499
H&K MK23 Disassembly/Field Stripping
- Clear the pistol!
- Depress slide release and allow slide to move forward.
- If applicable, remove any mounted accessories.
- Retract and hold the slide to the rear approximately 22 mm until the front end of
the slide release is centered on the recess visible on the left side of the slide (see
- Push the slide release into the recess on the right side of the frame. Lift and
completely remove the slide release from the left side of the frame (see Figure 10).
- Remove the slide with barrel and captured recoil/buffer spring assembly off of the
frame by sliding it forward (see Figure 13).
- Remove the captured recoil/buffer spring assembly from the barrel and slide by
lifting up on the rear of the guide rod. The entire assembly can now be lifted out
of the slide.
- Lift the rear of the barrel by the locking block and withdraw it from the slide.
- Threaded Connection for Mk23 Pistols.
- Weight: 15.4oz
- Length: 7.5″
- NSN: 1005-01-435-1917
- MSRP: ~$1300-$1500
The current batch of KAC suppressors come dual marked as MK23/USP models. Be careful when buying a KAC pistol suppressor, the thread pitch on the MK23 is M16x1 RH whereas the USP Tactical barrels are threaded M16X1 LH. Booster assemblies are available to purchase on a limited basis, but they can be pricey, running upwards of $600 alone.
Disassembly is easy, just unscrew the retaining ring and remove the complete Nielsen device (piston assembly).
The booster comes lightly coated in white grease from the factory.
The baffle design is unique compared to the current cone/K baffle trend. The KAC MK23 suppressor seems to be segmented into sections with raised humps pointing towards the center of the can and running parallel to the bore line.
The only part of the KAC MK23 suppressor that would appear to be user serviceable is an o-ring inside the piston.
Shooting The H&K And KAC MK23
My main concern about pulling the trigger on this duo for the first time was managing expectations. If the anticipation and build up of such an iconic setup was too much, the results could be a letdown. Luckily, this wasn’t the case – the MARK 23 with the KAC suppressor purpose-built for this gun is now one of the coolest gun combos I own. No, it’s not the quietest pistol suppressor, but it is quiet. Ringing steel at 50 yards with 230 grains in each round leaves a resounding thump/thwack that you can almost feel.
The double action trigger pull is long and deep, but incredibly smooth. And the single action pull is heavenly smooth. The size and weight of this combo makes recoil manageable, allowing for speedy followup shots. I have a M16x1 RH piston for the SilencerCo Octane 45HD and we’ll be doing some head to comparison in the weeks ahead (relax, I’ve only had the pistol for two days).
Now if you’ll excuse me, I have to go clear the Museum of Natural History and save all the hostages. And by “museum” I mean barn and by “hostages” I mean lawnmower.
Thanks for reading. Be safe and we’ll see you back here next weekend for another Silencer Saturday.
The Heckler and Koch Mark 23 may well be the finest production handgun ever made: Match grade accuracy, unparalleled reliability, and size that makes throwing it just as lethal as shooting it all play into it being a fantastic pistol. This behemoth of a gun was designed at the request of the United States Special Operations Command to fill a number of roles, and won the Offensive Handgun Weapon System competition which led to its adoption by a number of entities under the SOCOM umbrella. This time on TFBTV, Alex and Miles take a look at this .45 caliber German dumbbell.
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The Heckler and Koch MK23. It is THE handgun that I want for the apocalypse. It is the world’s first offensive handgun, and if that doesn’t get your adrenaline pumping, you might want to check your pulse. It is a 45 ACP pistol with a standard 12 round capacity. The Mark 23 is designed to be shot suppressed. It is designed to take an extraordinary amount of abuse and just……keep……working. It is not a gun I was prior a fan of, but frankly I had no time on one. After a day of running it, I can fully admit, I love this pistol.
The H&K Mk 23 pistol was developed in the 1990s for the US Special Operations Command and US Navy. The goal was to produce an “offensive handgun” that could serve as a primary armament for a special forces operator as well as a backup arm. It was required to be no more than 12 inches long, fit a suppressor and aiming module with laser and illumination options in both visible and IR spectrum, have at least 10-round magazines, chamber .45 ACP (specifically a 185gr +P loading), and pass a 30,000 round endurance test.
Here’s one that has been waiting in the archives for a year. This video is on the H&K MK23 Mod 0 offensive handgun system used by SOCOM, and the .45 Mark 23 pistol offered on the commercial/civilian market since 1996. Here we take one to the range, disassemble it, and just have a bit of fun.
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