MP5 ;HK54 :Original pre-designation model, introduced in 1964. It has a charcoal-gray phosphated finish rather than the matte black lacquered finish used on later models. The handguard resembles the "Slimline" handguard but is narrower and has slots along it. Its bolt carrier is longer and heavier than that of the final MP5, and it uses a flip-up "ladder" rear sight similar to that used on early G3 models. It uses straight steel magazines with plastic followers and distinctive "waffle" rib imprints for reinforcement. ;MP5 :The basic MP5, based on a modified and improved HK54, introduced in 1966. When first released, it had a gray phosphated finish, "Slimline" handguard, 8.9-inch barrel with "3-Lug" muzzle, and straight waffle magazines. Modernized improvements were introduced in the 1970s: Proprietary "claw mount" rails for scope, laser and flashlight attachments were introduced in 1973, un-ribbed curved magazines with chrome followers were introduced in 1977, the matte black lacquered finish was introduced for export models also in 1977 and the polymer "Tropical" handguard was introduced in 1978. ;MP5A1 :Standard MP5 with no stock and the "SEF" or "Navy" trigger group. ;MP5A2 :Standard MP5 with a fixed stock and the "SEF" or "Navy" trigger group. ;MP5A3 :Standard MP5 with a retractable stock and the "SEF" or "Navy" trigger group. ;MP5A4 :Standard MP5 with a fixed stock, the "Navy 3-Round Burst" trigger group, and a straight pistol grip. ;MP5A5 :Standard MP5 with a retractable stock, the "Navy 3-Round Burst" trigger group, and a straight pistol grip. ;MP5SF :Semi-automatic variant of the MP5 intended for the law enforcement and military markets, introduced in 1986 to meet a
Federal Bureau of Investigation request for a "9mm semi-automatic carbine". Unlike the HK94, the semi-automatic MP5 variant for the civilian market, the MP5SF retains its standard 8.9-inch barrel. It has two variants: the MP5SFA2 with a fixed stock, and the MP5SFA3 with a retractable stock. It uses the "0-1" trigger group, but since 1991, it has been delivered with select-fire bolt carriers that make it capable of automatic fire if paired with an appropriate trigger group. ;MP5PT :Training variants of the MP5A4 and MP5A5. They are designed to use a
plastic 9×19mm round developed by
Dynamit Nobel. ;MP5N :
Navy variant of the MP5, introduced in 1986 to meet a
United States Navy request for a submachine gun effective aboard ships and in low-light conditions. It is essentially an MP5A3 with a standard A3 retractable stock, "Navy Trigger" group (NT) which is a select-fire (fully-automatic) trigger group which excludes burst mode but features ambidextrous selctors,
tritium illuminated sights, and additional 1/2 x 32 threading forward of the "3-Lug" muzzle device, intended for mounting a
stainless steel suppressor produced by
Knight's Armament Company (KAC). ;MP5F :Improved French variant of the MP5, introduced in 1999 to meet a French
National Gendarmerie request for a suitable standard-issue submachine gun. It is essentially a modified and improved MP5A3, featuring a padded retractable stock, "Navy" trigger group, ambidextrous
sling mounts, and internal improvements to handle high-pressure ammunition. ;MP5 Mid Life Improvement (MLI) :Modernized refresh of the MP5, introduced in 2015. It is based on the MP5A5 and features the MP5F's padded retractable stock, triple-rail "Slimline" handguard, "Navy 3-Round Burst" trigger group, quick-release sight mount or sight rail, and a
RAL 8000 finish. Compatible components of the MP5 MLI can be switched out and retrofitted with other compatible MP5 variants.
MP5SD The
MP5SD ("SD" meaning
Schalldämpfer, German for "sound suppressor") is a variant of the MP5 with an integral
suppressor, introduced in 1974. The integral suppressor, built around its 5.7-inch barrel, uses a unique two-stage design that allows it to operate silently in most environments, including when wet, while still remaining reliable. The distinctive size of the integral suppressor gives it a unique handguard design, with a modified charging handle to account for it. The MP5SD has a rate of fire of approximately 800 rounds per minute, and is intended for use with both standard and subsonic ammunition. :Standard MP5SD with no stock and the "SEF" or "Navy" trigger group. ;MP5SD2 :Standard MP5SD with a fixed stock and the "SEF" or "Navy" trigger group. ;MP5SD3 :Standard MP5SD with a retractable stock and the "SEF" or "Navy" trigger group. ;MP5SD4 :Standard MP5SD with no stock and the "SEF" or "Navy" trigger group. It is largely similar to the MP5SD1. ;MP5SD5 :Standard MP5SD with a fixed stock and the "Navy 3-Round Burst" trigger group. ;MP5SD6 :Standard MP5SD with a retractable stock and the "Navy 3-Round Burst" trigger group. ;MP5SDN-1 :Naval variant of the MP5SD, with a retractable stock, the "Navy 2-Round Burst" trigger group, and the MP5N's KAC stainless steel suppressor. ;MP5SDN-2 :Naval variant of the MP5SD, with a fixed stock, the "Navy 2-Round Burst" trigger group, and the MP5N's KAC stainless steel suppressor.
MP5K The
MP5K ("K" meaning
Kurz, German for "short") is a redesigned compact variant of the MP5, introduced in 1976. Developed from the stockless MP5A1, it features a 4.5-inch barrel incompatible with muzzle attachments, an endcap with sling mount instead of a stock, and a unique handguard with a built-in foregrip. Most components of the MP5K are shortened on account of its compact design, including its bolt, receiver, charging handle, cover and trigger group frame. The lighter bolt gives it a higher rate of fire, at approximately 900 rounds per minute (as opposed to 800 rounds per minute with the regular MP5). Different variants of the MP5K use either unique open iron sights or redesigned fixed iron sights. ;MP5K Prototype :Stockless, cut-down MP5A2 with regular iron sights and an open vertical foregrip, developed in 1976. ;MP5KA1 :Standard MP5K with the "SEF" trigger group, smooth upper surface and small low-profile iron sights. ;MP5KA4 :Standard MP5K with the "Navy 3-Round Burst" trigger group and regular iron sights. ;MP5KA5 :Standard MP5K with the "Navy 3-Round Burst" trigger group, smooth upper surface and small low-profile iron sights. ;MP5K-N :Naval variant of the MP5K, with the "Navy" trigger group and a custom "3-Lug" muzzle similar to that of the MP5N. ;MP5K-PDW :"Full-size" variant of the MP5K, introduced in 1991. It is designed to provide the benefits of the MP5K with the size and handling of a regular MP5 and is essentially a regular MP5K with a custom folding stock, "Navy" trigger group, and 5.5-inch barrel with a custom "3-Lug" muzzle similar to that of the MP5N but for a
Qual-A-Tec suppressor. Its name is derived from its intended use as a self-defense firearm for vehicle and aircraft crews. ;MP5K Operational Briefcase :Standard MP5K intended for use with the
Spezialkoffer ("Special Case"), a custom
briefcase built by
Hofbauer GmbH with a modified claw mount for holding the MP5K, a
firing port and a
trigger built into the briefcase handgrip, introduced in 1978. Intended for security details in close-range defense or
suppressive fire situations, the MP5K Operational Briefcase uses a firing mechanism built into the briefcase to allow the MP5K to fire without taking time to remove it. However, it cannot be reloaded, cleared of obstructions or emptied of spent shell casings without opening the briefcase and detaching the MP5K. ;MP5K Special Bag :Variant of the MP5K Operational Briefcase introduced around 1978, using a leather
suitcase called the
Spezialtasche ("Special Bag"). Instead of using the handgrip as a trigger, the
Spezialtasche features a hidden opening that allows the user to discreetly reach into the bag and fire the MP5K directly. ;MP5 .22 Long Rifle Rechambering Kit :Rechambering kit to convert an MP5 to .22 Long Rifle, introduced in the early 1970s and discontinued at an indeterminate point. The kit consisted of a barrel insert, a bolt group, two 20-round magazines and was mostly sold to law enforcement agencies for training purposes by easing trainees inexperienced with the MP5 into learning handling techniques and firing practice without the high recoil and cost of 9×19mm rounds. The conversion reduced the MP5's rate of fire to 650 rounds per minute. It was ultimately replaced by the MP5 .22 LR in 2021. ;MP5 6.5×25mm Rechambering Kit :Rechambering kit to convert an MP5 to
6.5×25mm CBJ, which was proposed in the 2000s but never released. It would have allowed an MP5 to be rechambered simply by switching its barrel.
Civilian variants sight ;HK94 :Civilian market variant of the MP5, imported to the United States civilian market from 1983 to 1989 (with a one-off final order for the
California Department of Corrections and Rehabilitation delivered in 1991). It has a 16.54-inch barrel, "0-1" trigger group, push-button magazine release (as opposed to the paddle magazine release on regular MP5s), and a straight pistol grip similar to that on the MP5A4 and MP5A5. It has two variants: the HK94A2 with a fixed stock, and the HK94A3 with a retractable stock. Optional accessories included a handguard-mounted foregrip and a ventilated barrel shroud. The HK94 was particularly popular as a
prop in film and television productions of the era, and
blank-firing HK94s with "chopped" 8.9-inch barrels and fake automatic conversions were often used as cost effective MP5 stand-ins well into the 2010s. ;HK94/SG-1 :Accurized sharpshooting variant of the HK94, introduced in 1985. It was designed and intended for marksman fire in situations and environments where precise handgun cartridge fire may be needed, such as dense urban areas and indoor environments like prisons. It has a fixed match stock with a rubber buttpad and an adjustable cheekpiece, a folding
bipod, a
flash hider and a
Leupold 6x
telescopic sight. A
PSG1-inspired aftermarket trigger pack was also produced, featuring a target pistol grip and match trigger. The HK94/SG-1 did not sell very well due to its niche role and poor performance—it had poor range, penetration, stopping power and its Leupold scope was calibrated for
.223 Remington; not 9×19mm. Only 50 units were imported to the U.S., primarily to target shooters and firearm collectors. ;SP89 :Civilian market variant of the MP5K, imported to the U.S. between 1989 and 1994. To comply with the
National Firearms Act, the SP89 features a redesigned handguard that replaces the MP5K's built-in foregrip with an extended barrel shroud. Like all civilian market MP5 variants, it is semi-automatic only. ;SP5K :Modernized SP89 for the American civilian market, imported to the U.S. as a pistol in 2017. It largely resembles the SP89, with a redesigned extended barrel shroud and a top-mounted Picatinny rail for sights. Like all civilian market MP5 variants; it is semi-automatic only. ;SP5 :Modernized civilian market variant of the MP5 introduced in 2019, replacing the HK94. It resembles an MP5A2 with an 8.8-inch barrel, MP5K-style threaded adaptor, "Tropical" handguard, "0-1" trigger group, paddle magazine release, fluted chamber and the buyer's choice of fixed stock, retractable stock or endcap. ;SP5K-PDW :Modernized civilian market variant of the MP5K introduced in 2019, replacing the SP5K. It resembles an MP5K without its handguard foregrip. Like all civilian market MP5 variants; it is semi-automatic only.
Prototypes Five prototype firearms based on the MP5 were developed by Heckler & Koch in the 1980s and 1990s, mostly intended as improved variants or potential successors but were not developed any further. ;HK54A1 :Prototype improvement of the HK54, designed for the U.S. Navy
Naval Weapons Support Center Crane's (NWSC)
Joint Service Small Arms Program (JSSAP) in 1980. It was essentially a refreshed ambidextrous MP5SD with a redesigned retractable stock and compatibility with a 50-round drum magazine. It was designed to be suitable for
frogmen and
paratroopers in any environment. It was thus also designed to be reliably functional in extreme temperatures and while wearing bulky gloves. HK's proposal for the HK54A1 noted it could be converted to
.45 ACP if necessary. An unknown number were produced for testing purposes out of regular MP5 components. The HK54A1 was never properly developed for field use, but it met most JSSAP requirements, drawing the attention of the U.S. government and leading to the development of the SMG I and SMG II. ;SMG I :Prototype derived from the HK54A1, first developed for the JSSAP between 1982 and 1983. It was intended to spawn a "family" of modular all purpose submachine guns. Unique for HK, the SMG I used a simple blowback operation with separate lower and upper receivers and an easy-to-remove 5.8-inch barrel with an integral suppressor. It had a boxy body with a retractable stock and a diagonal foregrip. A mechanical and hydraulic buffer in the backplate and a timing device in the stock reduced its rate of fire to a manageable 500 rounds per minute, roughly half that of the HK54A1. The rear iron sight, resembling that of the
HK21E, allowed for adjustments based on wind, ammunition type, sight elevation and also featured indents to assist with close-range
point shooting. The trigger included an add-on to be used with bulkier cold weather gloves. Only 20 handmade examples were produced. The SMG I was tested by NWSC Crane in 1984 and proved promising but several minor issues prompted the development of the SMG II. ;SMG II :Prototype derived from the SMG I, developed around 1985. It has a largely identical design but addresses the issues reported by NWSC Crane. Its combination of the MP5, MP5SD and MP5K was made more clear. Analogous to the MP5 by default, the addition of a custom suppressor made it akin to the MP5SD. The removal of the suppressor and retractable stock converted it into an MP5K-like automatic pistol. The three-round burst fire setting returned from the HK54A1. Several components were made from plastic to reduce weight, while the over-engineered rear sight was abandoned for a simpler MP5 style sight. Uniquely, the SMG II had a gas cylinder in the handguard with a gas relief valve on the receiver, used to control round velocity and thus also sound. The "L" setting reduced the propellant gases to fire rounds below the speed of sound and thus without the usual crack of supersonic projectiles for almost silent suppressed fire, while the "H" setting used all available gas to fire rounds at full velocity for reliable unsuppressed fire. Other internal changes were made to reduce cost, simplify production and maintenance, but otherwise the SMG II was largely just an improvement of the SMG I. Like the SMG I, only 20 handmade examples were produced for testing by NWSC Crane. While the SMG II again proved promising, it was ultimately abandoned, not for budgetary or technical concerns, but simply due to the success of the regular MP5 and its derivatives, which were already popular enough with the U.S. Navy and all other potential customers to make a replacement unnecessary; HK ultimately developed the MP5N for the U.S. Navy instead. Allegedly, between 60 and 80 additional SMG IIs were secretly commissioned for an unidentified U.S. government agency, possibly a member of the
U.S. Intelligence Community, where they were favored by their users, but the lack of spare parts and the gradual move to higher caliber firearms for close-quarters combat led to all of them being retired and melted down for disposal some time around 1999. Technical knowledge from the SMG II and the concept of a universal submachine gun were later repurposed for the MP2000 prototype and the
UMP. ;MP5 PIP :Prototype developed around the late 1980s and early 1990s. Very little is known about the MP5 PIP or why it was developed, but it had a boxier body resembling the later UMP, a shorter diagonal magazine and the "flipper" charging handle later used on the
G36. Only one non-functional wooden
mockup was produced. ;MP2000 :Prototype derived from the SMG II, developed in the 1990s. It somewhat resembled the SMG II and featured a propellant gas-based round velocity silencing system similar to that of the SMG II. It was presumably an attempted revival of the SMG II concept to replace the MP5 for the 21st century. It is an immediate predecessor of the UMP, which was ultimately marketed as such. ==Other manufacturers ==