Heckler Koch Usp Serial Numbers

The Heckler & Koch Model 4 Pistol
by Dr. Stefan Klein and Ed Buffaloe

1. Heckler & Koch Parts
2. Heckler & Koch Usp 45
3. Heckler And Koch Usp 45 Serial Numbers
4. Heckler And Koch Usp 9mm
5. Heckler Koch Usa

Heckler & Koch Parts

The HK4 – first step to pistol production by Heckler & Koch

Today the name Heckler & Koch is synonymous with auto pistols and assault rifles for police and military use, but this was not always the case. This article will take a look at the origins of the Heckler & Koch Company and its first production pistol, the Model 4 (HK4) which was released in 1968. The name was chosen because the pistol was available with four interchangeable barrel and spring kits: .22 Long Rifle, 6.35 mm Browning, 7.65mm Browning and 9mm Browning Short.

Heckler & Koch Model 4, First Variant

Nov 13, 2019 Heckler and Koch is widely known across the planet for producing weapons like the HK G36 Rifle, the HK USP handgun and various other arms used by militaries and police forces across the planet. H&K Up for Sale – The HK G36 is one of the most prominent service rifles that H&K has produced. HECKLER & KOCH GMBH OBERNDORF / N MADE IN GERMANY. The right side of the slide is unmarked. The serial number is on the underside of the frame in front of the trigger guard. Early magazines did not have a magazine shoe. Later this was introduced for the customs police and eventually became available on the civilian market. In May 1995, Heckler & Koch introduced a.45 ACP variant. The USP Compact series was introduced in 1996 and is available in 9 mm Parabellum,.40 S&W,.45 ACP, and, exclusively to the Compact model,.357 SIG. Other variants of the standard USP include the USP Tactical, USP Expert, USP Match, USP Elite and the standard sidearm of the German Armed. Adjustable front and flip down rear.95% polished blue barrel and receiver with a few very tiny use marks.Checkered walnut stock,factory recoil pad, Bavarian style cheek piece,European size sling swivel hardware.Satin oil finish with a few light use marks.-$3000.00 2.Heckler & Koch HK 770 308 Winchester.Semi automatic with detachable magazine.

From today’s point of view none of the above calibers is particularly effective for self-defense. But the HK4 was somehow commercially successful, perhaps because it was accepted as a service pistol for the German Customs Police (Zoll), though it was never quite able to compete with the Walther PPK which was reissued by the Walther Company in the 1950s.

One of the owners of the Heckler & Koch Company, Alex Seidel, had been the primary design engineer behind the Mauser HSc (the Hahn- Selbstladespannpistole, Ausführung c) before World War II. So it is not surprising that the HK4 is closely related to the Mauser HSc. The idea of interchangeable barrels was not new either. In 1934 the August Menz Company had released the “PB Spezial” which was issued with interchangeable barrels in 9mm short, 7.65mm Browning, .22 centerfire and 4mm.

History of the Heckler & Koch Company

Heckler & Koch Model 4, Second Variant

Oberndorf am Neckar, in the far south of Germany, has been a center for weapon-making since at least 1812, when Frederick I of Württemberg established the royal weapons factory there. In 1897, the royal weapons factory, which had been manufacturing Mauser-designed rifles for some time, became Waffenfabrik Mauser AG, and later Mauser-Werke AG.

According to Weaver, Speed, and Schmid, in their book Mauser Pistolen: “Mauser-Werke AG, Oberndorf was targeted and bombed by the Allies on February 22, 1945. Physical damage to the facility was considered light, but the attack did serve to cripple the firm’s power plant...” After the war , the Allied Powers agreed that all weapons facilities in Germany were to be demolished, but the French were desperate for weapons for their new war in Indochina and their own infrastructure had been badly degraded, so they put the Mauser facility back into production through 1946, and even after that time, as they were shipping major machinery back to France, some arms-making activity may have continued.

Mauser had been the most important employer in the region and for many families it had been their only source of income. After the factory was closed, most ex-employees were completely out of work. Three former Mauser engineers, Edmund Heckler, Alex Seidel, and Theodor Koch, wished to support economic development and provide jobs. The obvious solution was to start a metal fabrication company, since they already had a trained workforce.

One on-line source states that the three sneaked into the Mauser factory to rescue much-needed equipment before it could be destroyed or removed, though Manfred Kersten states that the three negotiated with the French before the factory was demolished. The official company history on the Heckler & Koch website simply says they “...saved what they could from the ruins, thus laying the foundation for what was to become Heckler & Koch.”

The core of the new company was the Ingenieurbüro Heckler (Engineering Office Heckler) which Edmund Heckler founded in 1948. Heckler and Theodor Koch became partners and renamed Heckler’s company Heckler & Koch GmbH on 28 December 1949. The H&K company website states that, “Alex Seidel joined the team in 1949.” Why his name is not part of the company name is not explained.

Top: Mauser HSc Bottom: Heckler & Koch HK4

Early on, the company focused on parts for sewing machines. Later they produced parts for bicycles, household appliances, and office equipment. In a short time the initial production facilities were outgrown, so the company moved to the former barracks of the Reichsarbeitsdienst (Reich Labor Service) at the Lindenhof in Oberndorf.

Heckler & Koch enjoyed rapid economic success and in 1952 new factory buildings were erected. The company then focused on manufacturing gauges and specialized tooling and in 1955 it began production of military equipment. The company website states, justifiably, that Heckler & Koch helped rebuild Germany after it had been mostly destroyed during the war. They certainly had a major impact on the prosperity and economic growth of their region.

In 1955 Germany joined NATO and the German Bundeswehr (Federal Defense Service) was founded. Soon there was a demand for a new assault rifle which should be produced on German soil. In 1958 Heckler & Koch was chosen to produce the G3 rifle. Unfortunately Edmund Heckler did not live to see the great success of this product, as he died in 1960.

A few years later Heckler & Koch decided to produce a service pistol. Alex Seidel had been the primary engineer involved in the production of the Mauser HSc pistol, so the HSc design formed the basis for the HK4. The project originated in 1966 and the HK4 went to market in 1968.

The Heckler & Koch Model 4 (HK4)

The HK4 is a blow-back operated unlocked-breech semiautomatic pistol with a double-action trigger and an external hammer. Its name is derived from the tool-free interchangeability of the four barrels in calibers 9mm Browning Short, 7.65mm Browning, 6 .35mm Browning and .22 Long Rifle. The gun consists of four main components: slide, barrel and recoil spring assembly, frame, and magazine.

Early Box with Cleaning Rod Late Box with Screwdriver

The slide of the HK4 is made out of sheet steel, formed in a mold under high pressure, with front and rear plates welded in, and machined afterward . Early slides differ slightly from later ones. The slide holds the breech block, which is fixed by inductive soldering, as well as the breech block plate, firing pin and firing pin spring, safety lever, ejector and sights. Four small guide ribs are punched into the slide from the outside, two on each side--these ribs fit into grooves in the top of the frame in which the slide moves. Late guns have a riveted plate on each side of the slide bearing the inscription and slide serrations. (There are marked similarities between the HK4 slide and that of an experimental Mauser HSc pistol with a stamped sheet metal slide illustrated on pages 290-291 of Mauser Pistolen by Weaver, Speed, and Schmid.)

The barrels have six grooves with a right-hand twist. Early barrels in 9mm short and .22 long rifle have linear grooves in the chamber, four in the 9mm and eight in the .22. In .22 these grooves extend the full length of the chamber. When the round is fired the hot gases flow into the grooves and the case “swims” in the chamber. So Heckler & Koch was able to compensate for different case materials and qualities.

In the 9mm short barrel the grooves do not extend the full length of the chamber and are deeper at the center. In this case the pressure of the discharged shot forces the brass of the case to flow into the groove and thereby delays the opening of the breech. In theory these grooves allow for the elimination of a heavy slide and an overly-stiff recoil spring. This is not a new principle and was first used by the Fritz Mann Company in the Model 1920 Mann Pistol which had an annular groove in the chamber into which the cartridge expanded. The chamber grooves for both 9mm and .22 were eliminated in later production barrels, and so perhaps were not as necessary as the designer originally thought.

The strength of each recoil spring is specifically adjusted to the respective caliber. Hence each spring is fixed to its respective barrel so they do not get mixed up.

The frame is made of pressure cast aluminum, which is surface hardened. To compensate for the stiff recoil of the light slide, a buffer plate is attached to the slide stop at the front of the frame. Early buffer plates consist of a piece of steel sheet with a plastic element on the front. Late buffers have a piece of sheet steel on both sides. Grips are made of black or brown plastic and are attached to the frame from the back with a single screw.

The magazines hold eight rounds, except for the 9mm short which holds seven. The magazine bodies for the large calibers are all quite similar, though the .22 magazine has a distinctive look. Each magazine is inscribed with its caliber to prevent confusion.

Set of interchangeable barrels and recoil springs for HK4, with cleaning tool.

The rear sight, made of plastic, is fitted into a dovetail at the rear of the slide. The rear sight is locked by the breech block beneath it. To adjust the sight one must loosen the breech block plate, position the sight appropriately, and secure the breech plate again. The front sight is fixed to the slide by induction soldering.

The safety lever on the left side of the frame blocks the firing pin and pushes it down out of reach of the hammer. In the safe position the firing pin is additionally locked in position.

The hammer is designed in such a way that, whether cocked or not, no opening is left above or below it into which dirt or foreign matter might enter.

The HK4 came in a black plastic box with a green or red plastic inlay. We have also seen a few black paper boxes. Early pistols had a very simple cleaning rod, one end of which formed a screwdriver blade. Later pistols came with a red plastic screwdriver which contained a cleaning kit.

Early Manual - Left Late Manual - Right

The German manuals are quite interesting, because they show a possible technical evolution which we might not have noticed otherwise. Early manuals show the first variant slide and a pistol with black grips. This manual shows nine cartridges in the magazine instead of eight. In a later manual this was corrected with a simple ink stamp and we find a deletion on the same page which was done with a ball pen.

A later manual shows a late pistol which still has the early grips. The manual underwent some changes and also describes the new screwdriver. Perhaps there are more variants we have yet to discover. However, why do we mention this? The most interesting point is that the early cutaway drawing shows minor technical changes which were not mentioned in all the sources we have. We see differences in the length of the screw of the breech plate, the form of the striker, the hammer assembly, the magazine release, and the magazine which has a pin inside which limits the number of cartridges, etc. However, when we examine our pistols we realize that all our guns are as shown in the late manual. So , perhaps by accident, Heckler & Koch used an obsolete or incorrect cutaway drawing to illustrate the first HK4 manual.

Handling

HK4 Technical Data Length: 157mm Height: 110mm Width: 35mm Barrel length: 85mm Weight: 480 g Number of cartridges in the Magazine: 8 (7 for 9mm short)

The HK4 cannot be cocked with the safety engaged, but a round can be chambered. If the slide is retracted with no magazine, or an empty magazine, the slide will lock open. When a magazine is inserted the slide will close, and if the magazine is loaded the first round will be chambered automatically. The slide will not close with an empty magazine in the gun. Once the magazine is removed, the slide will close by pulling the trigger, whether the safety is on or off. However, the safety locks the firing pin and additionally moves it down so the hammer cannot contact it, so if the trigger is pulled with the safety on the hammer will fall but the gun cannot fire. When the magazine is dropped by more than 2mm and the slide is closed, the trigger is disabled and the gun will not fire. Additionally the pistol can only be disassembled with the safety on--you can press the barrel release, but the slide will not come off the gun until the safety is on. After the last shot the slide locks open. The gun can be carried safely with a round in the chamber and the safety on, whether the hammer is cocked or not.

Early guns have a very rough and heavy double action trigger pull in the vicinity of 9 kilograms, or about 20 pounds. The single action trigger pull is much lighter at about 1.7 kilograms, or about 4 pounds. According to George C. Nonte, writing in 1977, the later guns have a much improved double action trigger pull, though he still maintained that it was not as good as the Mauser HSc.

Disassembly

1. To disassemble the gun for cleaning or changing the barrel the safety must be engaged.
2. Remove the magazine and open the slide. Make sure the chamber is empty. Release the slide to its forward position by pulling the trigger.
3. Push the barrel release button at the front of the trigger guard. Move the slide forward and lift it from the frame.
4. Separate the barrel from the slide by pushing it forward against the force of the barrel spring (the magazine baseplate may be used for this purpose).

To change the HK4 from centerfire to rimfire:

1. Disassemble the slide and barrel as described above. (The safety lever must remain in the Safe position.)
2. Remove the screw that holds the breech-block faceplate and remove the faceplate itself.
3. Turn the faceplate around so that the letter ‘R’ is forward. (One side is marked with “R” for rimfire and one side is marked “Z” for centerfire.)
4. Guide the firing pin into the upper hole in the faceplate and reinstall the screw.
5. Before inserting the .22 caliber barrel press the extractor outward with the cleaning device and hold it. (The extractor has a vertical hole drilled through it toward the rear--once you pry the extractor out far enough you can put a pin, needle, or piece of fine wire through this hole to hold the extractor out of the way.)

Evaluation

Six shots at ten yards - 9mm K (.380)

The double-action trigger pull is impossibly heavy. One of us measures his at 20 pounds. (At first it was 21 pounds, but a thorough lubrication of the mechanism reduced it to 20. The double-action trigger on the Mauser HSc is much better, but we have been unable to determine exactly why the HK4 should differ so much. In the German manual HK calls the first shot “hingeworfener Schuss,” which we translate as “thrown shot.” Unfortunately, in a defensive situation the first shot is the most important and can often be the difference between life and death. On the other hand, the single-action trigger pull is a more reasonable 4 or 5 pounds. George C. Nonte, in his 1977 American Handgunner article, states that the later guns have a much better double-action trigger pull.

At the range, shooting one of the early HK4 pistols, we found the gun reasonably accurate in single-action mode--certainly suitable for self defense. Using the double-action, we were lucky if we hit the target. The sights are quite small and difficult to see. One of us found that the small spur of the hammer pinches the web if his hand during recoil. We experienced feeding problems with both hollow point and hardball ammunition in the 9mm Short (.380) caliber--this may be due to a weakened magazine spring. The gun is 45 years old and we do not know if it was stored with ammunition in the magazine.

Patents:

Some patents are specific to the Mauser HSc, but may also apply to the HK4:

• Patent-drawing for the safety, also showing the hammer design, Patent DE691840

  DE673766: Safety for firearm, registered 18 July 1935, granted 9 March 1939. This patent was an update to an earlier patent, DE670241.
• US2117826: Magazine latch mechanism, registered 20 August 1935, granted 17 May 1938. Alex Seidel.
• US2138213: Trigger and lockwork mechanism, registered 20 August 1935, granted 29 November 1938. Alex Seidel.
• US2177227: Trigger and safety mechanism, registered 20 August 1935, granted 24 October 1939. Alex Seidel.
• DE691840: Locking device for pistols, registered 21 August 1938, granted 9 May 1940. Alex Seidel. This patent was an update to the previous patent, DE673766.

Another patent related to the HSc was US2107359, granted to Ernst Altenberger for the HSc barrel retention mechanism. This patent was not utilized in the HK4, which used a redesigned latch that served the same function.

There are two patents specific to the HK4:

• Patent-drawing for the breech block faceplate, Patent DE1205425

  DE1428770: Automatic Pistol, registered 20 May 1963, granted 30 January 1969. Alex Seidel. This patent is very close to the HK4 in its final version. However, the major difference is that the original design indicated a separate breech block for each caliber (see also: US3227046, GB1004894, CH418896, BE648141, AT243132).
• DE1205425: Automatic Pistol, registered 18 February 1964, granted 18 November 1965. Alex Seidel. This patent describes the new breech block faceplate which has holes for center- and “one or more eccentric holes for guiding the striker for the use of rimfire cartridges” (see also: US3287843, BE659846, AT250219, SE301923, CH430504).

Variants

There are two primary variants.

The First Variant has 18 shallow flat-bottomed slide serrations at the rear, over the grips. The grips are of brown checkered plastic with a slightly raised thumb rest on the left side. The front of the slide is stamped with a stylized ModHK4. The three-line inscription, in all capital sans-serif characters, reads:

HECKLER & KOCH GMBH
OBERNDORF / N
MADE IN GERMANY

The Second Variant has a metal plate fixed to the slide which contains the inscription and serrations, such that the serrations are forward of the grips. Some have brown grips like the first variant, but later black plastic grips were provided with a slightly different design. The stylized ModHK4 stamp has been moved to the rear of the slide, behind the safety lever. The two-line inscription on the cover plate, in all capital sans-serif characters, reads:

HECKLER & KOCH GMBH
OBERNDORF / N MADE IN GERMANY

The right side of the slide is unmarked. The serial number is on the underside of the frame in front of the trigger guard.

Early magazines did not have a magazine shoe. Later this was introduced for the customs police and eventually became available on the civilian market.

H&R Centennial Commemorative HK4 HK4 with MAS Markings

Most HK4 pistols were sold to civilians, many in the US. The early U.S. importer of the HK4 was Harrington & Richardson, Inc. (H&R) of Worcester, Massachusetts. The guns have no special markings, but there is an insert inside the lid of the box that says “Harrington & Richardson, Inc.,” followed by the address, then “Exclusive U.S.A. Sales and Service for Model HK-4 Pistols.” The two U.S. patent numbers are provided in fine print.

In 1971 H&R imported a special edition of the HK4 (second variant) to commemorate the 100th anniversary of the company (serial numbers HR00001 to HR08700). On this version of the HK4, the nameplate contained the following inscription:

Harrington & Richardson Inc.
Worcester, Mass: USA
Made In Germany

To the right of the inscription was the circular H&R logo with 1871 to the left and 1971 to the right. Harrington & Richardson delivered the HK 4 to customers as a standard two-box set in .380 ACP and .22 LR. The first 2000 guns, serial numbers HR00001 to HR02000, came with a gold trigger and name plate in a red velvet-lined wood presentation case with extra barrel and screwdriver. The HK4 with serial numbers above HR02000 have the standard black nameplate and trigger.

A very limited number of four caliber sets were also imported by H&R and are much sought after by collectors. Additionally, we find engraved presentation pistols in very small numbers.

In the year 1974 Heckler & Koch sold 555 second variant pistols to the police of West Berlin. This was a little difficult because there were still some Allied restrictions on gun sales. So Heckler & Koch shipped the guns to the French MAS company (Manufacture des Armes de St. Etienne). The pistols have an MAS inscription and French proof marks, and are fitted with black grips. These pistols run from serial 51,566 to 52,120. The slide inscription on the left side reads:

MANUFACTURE NATIONALE D’ARMES
DE SAINT ETIENNE MAS

According to George C. Nonte, eventually H&R’s policy on importing guns changed and the HK4 was dropped. This probably happened sometime in 1974, as the HK4 is still listed as imported by H&R in the 1974 Gun Digest.

Security Arms of Arlington, Virginia had been importing other Heckler & Koch pistols, so they took up the HK4. An advertisement from the September/October issue of American Handgunner shows three H&K pistols and lists both company names: Heckler & Koch, Inc. and Security Arms Co., Inc., with the address in Arlington Virginia. HK4 pistols from this period are marked on the right side of the slide:

SACO ARL VA

or

SACO ARL VA 22201

and later

HK INC ARL VA 22201

or

HK INC Va

Advertisement from American Handgunner for September/October 1976

The HK4 is not listed in Gun Digest for 1975 and 1976, but appears again in the 1977 issue, listed as imported by the Security Arms Company of Arlington Virginia. In the 1978 issue of Gun Digest, the HK4 is listed as imported by H&K. Apparently, by 1978 H&K had opened its own subsidiary in the U.S., based in Chantilly, Virginia. HK4 pistols from this period are marked on the right side of the slide:

HK CHANTILLY Va

Jürgen Schönbeck reports that Heckler & Koch produced 38,200 pistols between 1968 and 1984 [3]. 25,800 were sold on the civilian market. Serial numbers for these civilian guns run from 10,001 to 35,800. He also reports that the German Custom Police (Zoll) received 12,400 pistols in 7.65mm Browning between 1970 and 1974 and that some of these pistols came with .22 long rifle barrel sets for training. Serial numbers run from 40,001 to 52,400. However, a certain number of these guns were later exported to the US. They have the HK CHANTILLY Va inscription on the right side and show the word “BUND” on the frame clearly indicating that the guns were made for the German Government.

There were also some engraved presentation pistols, though we have few details about them.

Heckler & Koch always claimed that the production of the HK4 was very cost efficient due to the deep-drawing process of the slide. Indeed the pricing of the HK4 was quite interesting. 1968 an HK4 in 7.65m browning cost 187 Deutsche Mark (DM). A Walther PPK cost 280 DM, so it was 50% more expensive. A Mauser HSc cost 240 DM in 1969. Barrel sets for the HK4 were 50 DM each

Summary

The HK4 was the first step the company made in the self-loading pistol market. It brought together the pre-war know-how of the Mauser engineers and staff and the with modern production techniques developed by H&K. The interchangeable barrels were an interesting marketing technique. August Menz had also tried to compete against the Walther PPK with his PB Spezial with interchangeable barrels, and H&K tried the same thing 35 years later. Ultimately both failed, although Heckler & Koch went on to become one of the premier weapon-makers of Europe. Once other H&K pistols in larger calibers were in regular production, the HK4 was phased out.

So the HK4 was, with the exception of the German Zoll and the Berlin Police, not very successful as a service pistol. Though it was moderately priced, production numbers did not approach the levels of the Walther PPK. By the end of production in 1984 it had to compete with modern self-defense and service pistols such as the Glock. The Heckler & Koch Model 4 may be considered one of the last dinosaurs of the blow-back era.

The Heckler & Koch USP and the Evolution of the H&K .45 Auto Caliber Handguns

ABOVE: Police Officer and SWAT Sniper Fabian Rivera firing the H&K USP Tactical. Notice the pistol is in full recoil. His SWAT team carried USP45 pistols up until the last few years when the department switched over to a new pistol and everyone in the department had to have the same pistol.

Traditionally, Heckler & Koch has been known for making some of the finest pistols and assault rifles in the industry. They have also had a major handicap that has prevented them from being as prevalent in the law enforcement and military market: the extremely higher than normal price. H&K has priced themselves out of much of the commercial and military market in the U.S. In 1989, H&K completed a study of the United States pistol market and came up with a set of criteria they would need to meet to compete with Glock, Beretta, SIG Sauer and Smith & Wesson. In September of 1989 work began on this new generation pistol. The criteria needed for this new pistol was to be affordably priced, conventional design, innovative features, reliable, durable, safe, accurate, high quality, advanced materials, large magazine capacity, low recoil, user friendly, many modes of operation and conventional locking system.

During these early days of research and development, another pistol opportunity presented itself. In February of 1991, United States Special Operations Command announced their Offensive Handgun Weapon System (OHWS) proposal. Much of the criteria for both pistols were the same and both pistols would use the same basic technology. The OHWS would be put through the toughest testing the world has ever seen for a pistol. In September 1991 the acronym USP or Universal Self-loading Pistol was assigned to the new family of weapons. The pistol was designed for the newly introduced .40 S&W caliber pistol. Unlike most of the other pistols in the industry, the USP was designed for this new caliber, not a 9mm pistol modified for the larger caliber. Prototype 1 was reviewed in February 1992 and the second prototype in June of 1992. In August of 1992, H&K delivered 30 OHWS pistols to SOCOM, which would eventually be adopted as the MK23 MOD O pistol. In September of 1992, the third prototype was reviewed and endurance testing began. In December, both the USP40 and USP9 completed the first half of the 20,000 round endurance testing. Upon completion, the USP design was frozen and production planning began. The USP was unveiled at SHOT Show in 1993 and in February 1993 USP production began at H&K GmbH in Germany. That same month the USP40 Variant 7 was submitted to U.S. INS/Border Patrol for evaluation. In April of 1993 the first USP40s arrived for sale at H&K Inc. for purchase, followed in June by the USP9.

The early pistols (USP40 and USP9) both operated from short recoil modified Browning-type linkless system. Sights provided were fixed partridge style, adjustable for windage and elevation. Standard white 3 dot and tritium sights were also available. The total length of the pistol is 7.64 inches with a barrel length of 4.13 inches. The barrel twist length for the USP40 is 14.96 inches and the USP9 9.84 inches. The width of the slide is 1.14 inches with the frame being 1.26 inches. The total weight of the USP40 with an empty magazine is 29.62 ounces and the USP9 is 28.46 ounces. The slide force on both pistols is 17.64 pounds.

One of the very unique features of the new USP pistol was that the fire control was offered in 10 different variants. Any pistol can be converted by an armorer to any of the variants offered. Both right and left hand controls were made available to the customer in an easy to reach location. They allowed for various modes of carry that include decocked safety on, decocked safety off, hammer cocked with safety on, double action only safety on as well as double action only no safety like that of a revolver.

• Variant 1: Single Action / Double Action with manual “Safe” position and safety/decocking lever (left side).


• Variant 2: Single Action / Double Action with manual “Safe” position and safety/decocking lever (right side).


• Variant 3: Single Action / Double Action without manual “safe” position with decocking lever (left side).


• Variant 4: Single Action / Double Action without manual “safe” position with decocking lever (right side).


• Variant 5: Double Action Only with manual “safe” position with safety lever (left side).


• Variant 6: Double Action Only with manual “safe” position with safety lever (right side).


• Variant 7: Double Action Only without manual “safe” position or safety/decocking lever.


• Variant 8: Double Action Only model that was especially configured for a U.S. government agency test in the 1990s. Never produced.


• Variant 9: Double Action / Single Action position and control lever with manual safety and no decocking function (left side). Cocked and locked version.


• Variant 10: Double Action / Single Action position and control lever with manual safety and no decocking function (right side). Cocked and locked version.

The pistol was designed to be a combat pistol, but as a safe to carry combat pistol. The basic variants (1, 2, 5, 9 and 10) have a manual safety. All have a double action mode of carry. All models have a passive disconnector safety that ensures that the slide must be in battery for the USP to fire. If the USP slide is out of battery, then the solid portion of the slide pushes the disconnector and therefore the trigger bar out of engagement with the catch and the hammer. The drop safety on the sear actuator latch blocks the hammer from striking the firing pin unless the trigger is pulled so when the hammer is in the decocked position, it is not in contact with the firing pin (like a 1/4 cock if you will) and the most important the firing pin block. The firing pin safety blocks the firing pin’s forward movement under spring pressure. When the trigger is pulled all the way to the rear, the tip of the catch is activated by the forward movement of the trigger bar and lifts the firing pin block out of position so when the hammer strikes the firing pin, the firing pin will be able to protrude enough from the breech face to ignite the primer. Early service pistols such as the Colt M1911 and the Browning High Power lacked this device and were prone to unintentional discharge by dropping the pistol on its muzzle from less than 5 feet.

The pistol uses the modified Browning-style locking system (linkless) that is a time proven mechanism that is combat demonstrated as well as allows for a simple, reliable, easy to replace barrel and is inexpensive to produce. Early USP barrels did not use H&K trademark hammer forged polygon rifled barrels. They opted for conventional 6 lands and grooves with right hand twist barrels. However, customers began to complain about the fact the barrels were not the hammer forged polygonal technology and H&K heard and listened to the customers. Within 2 years of production H&K went to their hammer forged barrels.

The slide release is extended rearward to make for easier actuation and also doubles for takedown of the pistol. The magazine release is also ambidextrous; it is activated from either side without the need for being swapped to the other side like most pistols of the time.

The slide of the USP pistol is manufactured by milling a single piece of 42 Cr Mo 4 steel. Machining is flawless, which is what you expect from H&K. The finish of the slide is called HE or Hostile Environment. The slide finish is extremely hard (732 HV1 Vickers), is corrosion resistant and is a proprietary nitrogen/carbon process. All other internal and external components are finished with a unique Dow-Corning “Molykote” finish that was tested and proven by the German Navy Kampfschwimmer (Combat Swimmers). All parts are finished in this making them resistant to corrosion and wear due to the non-reflective finish. The extractor is aggressive and pivots on its center axis. When looking at a USP40 and a USP9 slide from the bottom you can easily see where much material has been removed for use with the lower power 9mm cartridge

One of the most interesting aspects of the USP is its use of a proprietary glass fiber reinforced polymer material the frame is made out of. Molded into the frame are metal guide rails as well as the serial number plate. H&K is not new to polymer frames. They, in fact, predate Glock with the VP70, G11 and CAWS. This strong polymer is actually in many ways stronger than steel. The polymer absorbs recoil rather than have impact of metal on metal, which will wear on the metal. There are tear-away grooves allowing the shooter to grasp the magazine and remove it if it should become stuck. The trigger guard is very oversized permitting those with winter gloves the ability to manipulate the trigger. Like any good service pistol, the pistol incorporates a lanyard lock. The texture is stippled and grooved with the stippling on the front and backstrap quite aggressive – in fact some may say too aggressive. People have been known to take a file to them to dull them down a bit. Certainly they are anti-slip.

The magazines for the pistol are manufactured from the same material as the frame of the pistol. They contain a stainless steel insert to insure uniformity and that the magazines will drop free from the magazine well. The USP40 magazine contains 13 rounds and the USP9 contains 15 rounds. On the rear of the magazine are witness holes so the shooter can see exactly how many rounds are in the magazine by simply looking at the back of the magazine.

Perhaps the crowning achievement H&K accomplished with this pistol is the U.S. Patent Number 5,309,815 (May 10, 1994) mechanical recoil reduction system that was first used in the development of the OHWS/MK23 pistol. This devise reduces the recoil force by up to 30%. This adds many features to the pistol. First and foremost it reduces stress on the components of the pistol. This results in longer service life even when using +P or +P+ ammunition. One of the requirements for the OHWS/MK23 was its compatibility with +P ammunition, which would eventually destroy an M1911-type pistol. In turn, the mechanism reduces felt recoil to the shooter. This also makes for a pistol that has decreased sensitivity to ammunition variations. This mechanism makes the USP one of the few pistols on the market at the time that could handle the high pressures associated with the .40 caliber round as well as have a 9mm pistol that could handle without issue a steady diet of +P and +P+ submachine gun ammunition without damage to the pistol. The life of the frame of the OHWS/MK23 surpassed any pistol on the planet. The USP shares this as well.

The USP was one of the first pistols to have a Universal Mounting Groove (UMG) on the front of the frame. This was pre-Mil-Std 1913 rail. This UMG allowed easy installation of lasers, flashlights and optical sights. The groove made the accessory parallel with the bore and was exceedingly more secure than mounting to the trigger guard.

Testing of the USP40 was significant. The pistol was tested and passed the military (NATO) testing procedures. These far exceed the testing standards the industry does for commercial products. The NATO test included tolerance inspection on trigger pull, firing pin energy/protrusion, headspace, velocities, etc. The controls and safeties were tested as well as testing with two Winchester DP40 proof loads. Targeting testing included zeroing at 25 meters (point of aim/point of impact) and ammunition compatibility (as of this time more than 85,000 rounds had been fired thought the USP40). The accuracy testing showed the most accurate being 3.2 to 3.9 inches with Winchester 155 grain Silver Tip Hollow Point and Remington 155 grain Jacketed Hollow Point. Reliability testing consisted of 20,000 rounds fired in various attitudes. Parts were checked for damage every 1,000 rounds. The slide was cycled manually 1,000 times after firing every 10,000 rounds. Test results showed no normal wear detected in less than 5,100 rounds. The pistols performed flawlessly in the testing. Also conducted was a barrel obstruction test where a live round was fired with a projectile positioned at the forcing cone and another test with the projectile inserted 1.18 inches into the muzzle. There was no damage to the pistol and accuracy was unaffected. The pistol was submitted for drop testing and the pistol was dropped on all six sides plus 45 degree top of muzzle onto rubber from a height of 4 feet as well as six times onto cocked hammer on steel and concrete from a height of 3 to 6.7 feet with no ignition of the primed cartridge case nor any indent on the primer. Fouling testing consisted of the pistol firing 1,000 rounds without cleaning or lubrication. No malfunctions had occurred. The last portion of the test was environmental, which consisted of low temperature (-51 F), high temperature (145 F), thermal shock (-50.8 to +145.4 F), mud bath (10 minutes exposed), sand (10 minutes) and freezing rain (1 hour to -50.8, sprayed with water to .039 to .118 inches thickness). The USP40 passed all testing.

The USP was an instant hit in the United States with both commercial and LE customers. The MK23 Mod 0 was less successful with SOCOM due to no fault of the pistol. It was truly the most advanced pistol in the world. But the size was the problem. It was too large for the operators to carry. They got accustomed to the low recoil 9mm caliber pistols with 15 round magazine capacity such as their SIG Sauer P226 pistols. So unfortunately this pistol never saw the use for which it was designed. But the pistol was a success in that it did exactly what SOCOM wanted. There was a gap now in the USP line up. Although it was built for the American market, it was not in America’s caliber, 45 Auto. Soon after the release of the USP40 and USP9 the market asked for a USP pistol chambered in the classic American caliber. At SHOT Show 1995, the American prayers were answered. The USP45 was basically a USP40 on steroids. The USP45 clearly showed its lineage with the MK23 minus the threaded barrel and without the rubber O-ring. The USP45 retained the USP fire controls as opposed to the MK23 with its separate decocking lever and safety. The USP45 was of course slightly larger. The barrel length is 4.41 inches long and the pistol 1.90 pounds compared to the USP40 weighing 1.74 pounds. The height of the USP45 is 5.55 inches compared to the 5.35 inches of the USP9/USP40. The overall length is 7.87 inches compared to the 7.64 inches in length of the USP9/USP40. At the time of its introduction, the U.S. Crime Bill was in effect limiting magazine capacity to 10 rounds. The non restricted magazines held 12 rounds of .45 Auto caliber ammunition. The pistol had the polygonal rifling from the beginning. The pistol was also an instant success. This pistol got attention from law enforcement as well not only as a duty weapon but also as a SWAT weapon. It was adopted by the City of Rochester New York Police Department Emergency Task Force as their sidearm. The recoil was less than any other pistol of its caliber. The true nemesis of the USP45 is the Glock 21. Special Operation groups liked the USP45 as well. Although similar in design to the MK23, the USP45 was much smaller making it an excellent sidearm in .45 Auto caliber. The MK23 was designed to be an offensive weapon, part of a three piece system including the pistol, a laser aiming module and a sound suppressor. The USP45 was comparable in size to that of the SIG Sauer P226 they had carried. The USP45 and soon to be introduced other variants would not become truly realized until the onset of the Global War on Terrorism after the September 11, 2001 attack. For the first time since the Vietnam War, American soldiers would be involved in infantry and special operation engagements on a foreign land. The troops and operators found out really quick the benefit of a .45 caliber handgun over the 9mm pistol they were so fond of in peace time training.

The T&E pistol, as requested, was the traditional and most common version of the USP 45 pistol: the Variant 1, which has a safety, decocker as well as permits carrying in the cocked and locked position. This pistol has gone through incremental improvements since its introduction. The sights on this pistol are the common 3-dot system with white dots. The pistol performed flawlessly and was very accurate with offhand groups at 15 yards under 2 inches.

The USP45 spanned a wide array of uses – the commercial market, self defense, competitive shooting, law enforcement as well as military. The pistol could be modified to fit each of those applications that much better.
The USP45 Compact

In 1997, H&K introduced their next version of the pistol, the USP45 Compact. This pistol was only 5% larger than the 9mm version with a 3.78 inch barrel and an overall length of 7.09 inches. The magazine held 8 rounds. To make for a more snag free design, the hammer of the pistol was bobbed. This pistol too had the proprietary mounting groove. The USP compact only employs a polymer absorber bushing due to the length restrictions on the compact guide rod. The bushing does not reduce recoil; it simply stops the slide from directly engaging the frame after firing. The weight of the pistol is only 1.76 pounds.

The USP45 Tactical

The MK23 Mod 0 was without a doubt the most advanced pistol in the world but as previously stated very large. The pistol was nicknamed the “crew served pistol” by those who used it. The demand came from the customers for a USP45 pistol with all of the advanced features of the MK23. In 1998 that pistol was introduced: the USP45 Tactical. The 5.09 inch barrel incorporated the O-ring of the MK23 to increase accuracy as well as the muzzle of the barrel was threaded to accept a sound suppressor. The weight of the USP45 Tactical is 2.05 pounds compared to the 2.46 pounds of the MK23. The overall length of the USP45 Tactical is 8.64 inches compared to 9.65 inches of the MK23. The sights are high profile for use with the sound suppressor. The rear sight is fully adjustable for windage and elevation as well. The trigger is improved with a match single and double action. The trigger has an adjustable trigger stop to eliminate trigger over-travel. Like the MK23, the pistol has the patented recoil reduction system. The extractor doubles as a loaded cartridge indicator. The same 12-round magazine is used in this pistol as the standard USP 45.

The T&E pistol is quite impressive and it is easily seen why one may prefer this over the MK23. It is smaller and does everything the giant crew served handgun will do. This pistol proved to be the most popular with the police/SWAT officers that tested the firearms with this author. The sights proved to be extremely accurate and the groups tightened up a little off hand. On a bench the groups tightened up to an in to an inch and a half with Hornady Critical Duty 220 grain +P ammunition.

The Mark 23

Like most military weapons, the commercial market wants the same high-tech weapons as the military. Once the story broke of the history and developments of the MK23 Mod 0 pistol there was an immediate commercial demand. H&K responded with the Mark 23 in 1998. There are only two real differences between the two pistols. The Mark 23 has the SAAMI spec .45 Auto chamber and the marking on the slide differentiates the military model from the commercial version. This pistol always carried a hefty price of nearly US$1,800 but they have always sold as many as they could produce.

The USP45 Match

The 3-gun shooters as well as combat pistol shooters requested a model of the USP45 that was more geared for competition. In 1998, H&K introduced the USP45 Match. This pistol is the basic USP45 with some very significant changes. The rear sight is a target sight with a micrometer for adjustments in windage and elevation. The barrel length is extended to 6.02 inches. There is a custom barrel weight assembly added to perfectly balance the weight of the pistol. The pistol has a 10 and 12 shot magazine. The weight of this pistol is 2.38 pounds with an overall length of 9.45 inches. The trigger has an adjustable trigger stop for precise let off.

The USP Expert

Heckler & Koch Usp 45

Introduced in 1999, the USP45 Expert has many modifications from any previous pistol. The control lever is on both sides of the frame making it fully ambidextrous. The slide has been elongated to assist in balance and to cover the longer 5.20 inch barrel. The trigger is match grade in both single and double action along with an adjustable trigger to eliminate over-travel. The barrel has the O-ring for increased match accuracy and the extractor also works as a loaded chamber indicator. Like all before it, this pistol too has the recoil reduction mechanism. The pistol weighs in at 2.30 pounds with an overall length of 8.74 inches. Both 10- and 12-round magazines are offered.

The USP45 Compact Tactical

This pistol is the basic USP45 Compact pistol with a threaded barrel to accept the sound suppressor. The magazine holds 8 rounds. The hammer is bobbed so not to snag on clothing. The barrel length is 3.78 inches with an overall length of 7.09 inches

The USP45 Elite

This too is a modified pistol for the combat shooter or special operation operator. The slide has been extended to cover the 6.02 inch barrel to both extend the range of the pistol and to balance the pistol. The barrel has the O ring to increase accuracy as well. The trigger is also a match trigger with an adjustable trigger stop. The pistol can be had with both a 10- and a 12-round magazine. Target sights are standard with the rear sight having a micrometer for adjusting both windage and elevation. The pistol has an overall length of 9.45 inches which is comparable to that of the MK23. This pistol also features a chamber loaded indicator.

Heckler And Koch Usp 45 Serial Numbers

The HK45

The HK45 is the newest member of the H&K 45Auto family of weapons. It is actually quite different than the USP. This also marks the first American made USP pistol manufactured in the New Hampshire plant. The overall size is actually smaller than that of the original USP40/USP9. The grip is similar to that of the P30 series with modular backstraps to accommodate the size of the individual shooter’s hand. The frame is also equipped with a Mil-Std 1913 accessory rail. The slide is contoured and radiused with a forward slide gripping groove. The safety lever is an improved slimmer contour. The slide catch lever is on both sides making the pistol fully ambidextrous. The barrel is 4.47 inches with traditional polygonal rifling. The barrel is equipped with the accuracy enhancing O ring. The weight of the pistol is 1.95 pounds with an overall length of 8.03 inches. The magazine is not the standard USP 45 one but modified to accommodate the thinner grip. This magazine has a capacity of 10 rounds. The T&E pistol was also equipped with TRU DOT tritium night sights. The sights are standard so they would not be able to be used if the pistol was to be equipped with a sound suppressor. This pistol does not share the recoil reduction mechanism of the USP full size and MK23/MARK23 pistol but the one used in the compact type pistols. The extractor doubles as a live cartridge indicator.

The T&E pistol shot flawlessly. This is the new series HK45 version of the USP Tactical. The grip was noticeably smaller. Those with smaller hands commented on their preference for it. There was really no noticeable recoil difference given the different recoil reduction system. The USP Tactical has the edge on accuracy but that could be attributed to the USP Tactical having target sights instead of combat sights (three dot).

The HK45 Compact

Heckler And Koch Usp 9mm

This is the compact version of the HK45. The barrel is 3.90 inches long with an overall length of 7.27 inches. This small package packs 8 rounds of .45 Auto ammunition and keeps all of the advanced features of the HK45 but in a smaller package. The barrel also has the rubber O-ring for increased accuracy. To assist in concealment the hammer is bobbed to avoid snagging on clothing. This pistol comes standard with TRU DOT tritium night sights. The slide is low profile and slim lined for ease of concealment. The entire pistol weighs 1.78 pounds with an empty magazine. The T&E pistol is equipped with the LEM trigger system. The extractor also doubles as a loaded chamber indicator. This, like its bigger brother, has a Mil-Std 1913 rail on the front of the frame.

Heckler Koch Usa

This T&E pistol is perhaps the most impressive of the lot; mostly due to it being compact with the recoil of the full size. There was little noticeable recoil in the smaller gun. This author has very large hands and was able to grip the pistol firmly. The LEM trigger proved to be very nice and very accurate.

The HK45 Compact Tactical

This pistol is identical to the HK45 Compact with a couple additions. The first is a 4.57 inch threaded barrel to accept a sound suppressor. It also comes with a 10-round magazine and a extended floorplate and grip backstrap. The increase in weight is negligible at 1.82 pounds, only 4 ounces different.

Although the USP is 20 years old, it is still state-of-the-art. H&K continues to build on it modernizing it for the changing times. The USP series pistol is in service throughout the world, although not necessarily in .45 Auto caliber. There is no doubt that the .45 Auto is America’s caliber and will be with us for a very long time. Deep rooted in tradition as well as a well backed up reputation make it one of the finest combat pistol calibers of all time. H&K has undoubtedly been on the forefront of modernizing pistols to fire this over 100 year old cartridge with the MK23, making the most advanced handgun in the world using this proven cartridge. The American market will continue to procure pistols from H&K in this caliber and by Americans I mean commercial, law enforcement as well as military. These pistols have seen service with American forces in the Global War on Terrorism as well as many other places throughout the globe including the MK23, USP45 and the USP45 Tactical models. The adaptability to any trigger variation has also put this gun on the list for law enforcement. Although not the most popular caliber abroad, the pistols in their 9mm variations are in use by the security forces of Australia, Denmark, Estonia, France, Germany, Greece, Ireland, Japan, Lithuania, Luxembourg, Malaysia, Poland, Portugal, Singapore, South Africa and Spain. Also in that lineup are numerous U.S. military and law enforcement agencies. These are top tier pistols used by top tier operators.