The HK45CT is shipped with low-profile tritium night sights, but it can also be ordered with high-profile sights.

The HK45CT is derived from three pistols designed in 2006 with the consultation of Ken Hackathorn and Larry Vickers, both of whom run advanced tactical training schools and have years of military and firearms instructional experience. They were hired to help design a .45 ACP pistol for the Joint Service Pistol competition. This project was shelved without a competition occurring, but three of HK’s bestselling pistols resulted: the HK45, HK45C and the P30, which comes in .40 or 9mm.

The HK45CT is designed for professional users in Tier 1 military units who require an accurate, reliable and suppressor-capable pistol. The “CT” in its model name stands for Compact Tactical and has certain additional features that the HK45C does not. These include a threaded barrel, night sights for use with a suppressor and magazines that hold 10 rounds instead of eight.

Equipped with 11 rounds of .45 ACP firepower and ready to be suppressed, the HK45CT was recently adopted by the U.S. Naval Special Warfare Group as MK24 MOD 0 Combat Assault Pistol. Shown here with a Viridian X5L laser/light.

Besides HK45CT, Heckler & Koch produces four other suppressor-capable pistols, three of which are chambered in .45 ACP: the USP Tactical, USP Compact Tactical, and the MK23. Though each of the .45-caliber pistols have been used by Tier 1 military units, the MK23 is the pistol that was extensively tested starting in 1991 to fulfill USSOCOM’s need for an accurate, suppressor-capable weapon smaller than a submachine gun. After two prototypes and only a few modifications, including the elimination of a slide-lock device designed to reduce mechanical noise when using a suppressor, the MK23 became a fielded weapon of U.S. Special Operations troops in 1996.

USSOCOM never acquired the total possible number of contracted pistols. The MK23 performed well, but it’s larger than it needs to be, and the concept of an “Offensive Pistol” never made sense to the operators who used it. The MK23 is 9.6 inches long and when equipped with the Knight’s Armament suppressor it was intended to use, the unit measures 16.6 inches. At one convention I attended, a SEAL explained that he would much rather carry an HK MP5K compact submachine gun that is only slightly larger than the MK23 but offers vastly more firepower than the MK23 with its 12-round magazine.

According to news reports, the Navy chose the HK45CT as the replacement for the MK23 early in 2011 and designated it the MK24 MOD 0 Combat Assault Pistol. This pistol is equipped with the Ti-Rant 45S suppressor from Advanced Armament Corp. and a waterproof infrared laser made by Crimson Trace that mounts below the barrel on the Mil-Std-1913 rail. The complete system measures 14 inches in overall length.

To facilitate racking the side with one hand, the rear sight has a cocking ledge. The decocker/safety also
allows operators to carry the HK45CT cocked and locked.

Gun Details
The HK45CT is a compact pistol that uses the familiar modified Browning tilting block, locked-breech design. It has a polymer frame made in Heckler & Koch’s New Hampshire factory and the steel slide assembly and magazine are imported from Germany. This is a quality firearm with all parts fitting tightly and the finish evenly applied.

The HK45CT has a narrower grip than the USP Compact .45 ACP. It fits a wider range of users yet does not sacrifice magazine capacity compared to the USP. The HK45CT is available in several variants that differ with respect to inclusion of a decocker and placement of a control lever that functions as either a safety or combination safety/decocker. This pistol is ideal for left-handed shooters because other variants have this lever on either side or both. The HK45CT can also be ordered with a safety lever only and no decocker.

The slide assembly is steel, as are four small rails molded into the polymer frame. A nylon buffer surrounds the captive recoil spring. Buffers absorb some of the recoil, making follow-up shots easier, but they must be mated to the proper-strength recoil spring and can also lead to stoppages if the shooter limp-wrists the handgun. This is particularly important when using a suppressor, since the added weight and leverage of a suppressor can cause stoppages if the slide velocity is inadequate to cycle the action.

The HK45CT’s ergonomics are very good. The grip has a molded crinkle texture on the frontstrap and backstrap. Changing the size of the grip is a matter of removing a 1/8-inch roll pin from the backstrap and replacing it with a smaller one supplied with the pistol. The 10-round magazine acts as a grip extension. Eight-round magazines that come with the HK45C fit as well. The two additional rounds extend the magazine about an inch, and the extended portion of the front of the magazine provides more gripping surface for the pinky finger. However, the 10-round magazine makes this compact pistol 0.75 inches taller than a full-size HK USP.

Spec-ops personnel need to be able to work in any environment. The HK45CT allows operators to mount several accessories, including this Viridian X5L laser/light combo, so target acquisition is assured in all conditions.

Other ergonomic features include the ambidextrous slide and magazine releases. The slide release levers are longer than those found on most pistols and are designed to be thumb operated with the firing hand without adjusting your grip. This method works well as a quick method for chambering the first round. The magazine release levers are on the rear of the triggerguard. This type of release is designed to be trigger finger activated, not using the thumb, as with push-button safeties. To release the magazine, simply index your trigger finger on the bottom outer edge of the triggerguard and slide your finger rearward to the lever. Underscoring this pistol’s finer engineering, the triggerguard flares outward just ahead of the magazine release levers and is intended to protect them when the pistol is holstered.

The HK45CT can be safely carried in a proper holster with a round in the chamber because it has an internal device that locks the firing pin until the trigger is depressed. It can also be safely carried with a round in the chamber and the safety on (i.e. “cocked and locked”). This affords the user the benefits of a consistent and relatively light single-action trigger stroke on both the first and subsequent shots. This helps shot placement compared to firing the first round using a longer, heavier double-action trigger pull, then subsequent rounds with a shorter, lighter single-action pull. When carried cocked and locked, be sure to use a proper draw: Keep your finger outside the triggerguard until you are on target and place the safety into the fire position only after the pistol clears the holster and is starting to point towards the target.

The cold-hammer-forged barrel has polygonal rifling that is suitable only for jacketed rounds. Using lead bullets can cause lead to accumulate just ahead of the chamber, which can increase chamber pressure. Though the pistol can use +P or +P+ ammunition, HK cautions that accelerated wear from using these high-pressure rounds can result.

A high-temperature rubber O-ring on the barrel just behind the suppressor threads is a major contributor to this pistol’s outstanding accuracy.

One of the most desirable features on the HK45CT is its very good accuracy, which in large part is due to a high-temperature rubber O-ring that fits into a groove in the barrel about 0.33 inches from the muzzle. This ring keeps the barrel-slide lockup consistent and tight, and is used on all of HK’s .45-caliber suppressor-ready pistols, as well as the competition Elite model. A thread protector is missing from the package, which would be handy given the fine thread pitch used.

The HK45CT is equipped with steel tritium night sights in the three-dot pattern, giving a crisp sight picture that is easy to pick up in day or night. Sights can be ordered with either a low- or high-profile design to give a sighting plane above the suppressor. Either version’s rear sight has a cocking notch on its leading edge that is designed to catch onto a belt buckle or the edge of a holster and allow the user to rack the slide using one hand if he is incapacitated. Both front and rear sights are mounted in dovetails and can be adjusted for windage by drifting.

The HK45CT features a ubiquitous Mil-Std-1913 rail on the dust cover for mounting flashlights or lasers, and the slide has forward serrations for press-checking the chamber. One of the subtler and well-conceived design enhancements of this pistol is the reduction in slide width from bottom to top. This profile, in combination with a frame that is only 1.14 inches thick (excluding the safety), makes concealed carry more comfortable when using an inside-the-belt holster. There’s no thick, blocky feel to this pistol, and the tapered profile of the slide tends to bring my focus up to the sights quicker than pistols with square profiles.

Barely visible red paint on the edge of the HK45CT’s extractor warns of a loaded chamber, and a discreet internal key-activated mechanism locks the slide, trigger and hammer.

The HK’s 10-round mag comes with a baseplate that allows for a better grip, making the pistol easier to control. The mags extend the height of the pistol by 0.75”.

Long, easy-to-reach slide release levers are ambi and standard on this compact .45. It can also be ordered with an ambi safety/decocker.

Shooting Impressions
The HK45CT performed well with all types of ammunition tested. Accuracy firing, done off a Caldwell rest at 15 yards, was excellent. The average group size was less than 1.5 inches center to center. This pistol seemed to prefer 230-grain loads and the best group was fired using Black Hills’ newly manufactured “red box” 230-grain FMJ, which produced one ragged hole of 0.63 inches and the best average group of 0.91 inches. The Black Hills load also gave significantly higher velocities. Winchester Supreme 230-grain JHP and Federal Personal Defense 185-grain JHP also shot well, with respective average groups of 1.19 and 1.28 inches. Because the sights, grip and single-action trigger were very good, accuracy testing could easily have been done at 20 yards without becoming tedious. Reliability was perfect, with no stoppages or malfunctions of any kind when using five types of ammunition.

The double-action trigger pull is a manageable 0.5 inches long, but lets off at a hefty 12.2 pounds when measured with the hammer fully forward. Curiously, when the hammer is not fully forward after using the decocker, the weight is reduced to 11.2 pounds. The single-action pull is 4.75 pounds when measured with a Lyman electronic trigger weight scale and broke with minimal creep and slight over-travel. Because the double-action pull is so heavy, carrying the pistol “cocked and locked” makes for a much more accurate first shot on target, which is critical in a gunfight.

The HK45CT is a very controllable pistol due to the recoil-reducing buffer system, grip design and magazine extension used on the 10-round magazines. Though the 12.2-pound DA trigger pull is heavy and difficult to master, combat accuracy is achievable with practice. The SA trigger has a short reset and double-taps are easy to deliver accurately.

Though the HK45CT has a relatively heavy trigger pull at 12.2lbs, it’s an extremely accurate pistol.

One criticism of having the decocker incorporated into the safety lever is the possibility of drawing the HK45CT from the holster in a cocked and locked condition but inadvertently decoking the mechanism. This would occur if a user attempts to disengage the safety and pushes the lever beyond the “Fire” position and into the decocked position. Shooters who feel this is a risk can order the pistol without a decocker and with a safety lever only.

Final Notes
Though the HK45CT is a professional’s tool that has all the necessary elements to fulfill the covert missions special operations soldiers perform, its caliber, size, features and reliability make it well suited to concealed carry by civilians. It is adaptable to different users and modes of carry because of its changeable backstraps, different trigger and safety variants, and ability to be carried hammer down or “cocked and locked.” Available eight-round magazines with finger rests and a suppressor-ready barrel enhance its flexibility. Accurate and reliable with every load I tested, this well-made pistol is an excellent choice for those who want a compact pistol with .45 ACP power. Find out more by calling 706-568-1906 or visiting

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