Artillery

120 mm UBM-52

Also known as
  • UBM-52
  • UB M52
  • M52UB
  • Universal Mortar UB M52
  • Minobacac 120mm UBM52
  • Minobacac 120 mm UB M52

The 120 mm UBM-52 is a Yugoslav heavy mortar designed by the Military Technical Institute Belgrade as a lighter, wheeled alternative in the Soviet 120 mm mortar lineage. Croatian archive-derived reporting documents UB M52 mortars with Croatian police and ZNG-linked defenders around Otočac during the 1991 Croatian War of Independence.

120 mm UBM-52, 120 mm heavy mortar, Artillery
Image source: Wikimedia Commons UB M52 7242

Role in Conflicts

Profile / Specs

Profile

Origin
Yugoslavia
Built in
YugoslaviaSerbia
Type
120 mm heavy mortar
Service note
Entered service in the early 1950s; documented in limited service and reserve inventories
Designer
Military Technical Institute Belgrade
Designed
1948-1951
Produced
1952 onward
Number built
At least several hundred reported by WeaponSystems.net
Developed from
Soviet 120 mm PM-38 / PM-43 mortar lineage
Developed into
Later Yugoslav 120 mm mortar families, including the M74 and M75 light mortars

Specifications

Caliber
120 mm smoothbore mortar
Crew
5
Weight
About 400 kg complete; barrel 92 kg, baseplate 68.5 kg, carriage 237 kg
Barrel length
1.85 m
Rate of fire
25 rounds per minute maximum for up to one minute; 10 rounds per minute normal; 70 rounds per hour sustained
Range
4.8 km with heavy shell; 6.1 km with light shell; 195 m minimum with heavy shell
Carriage
Fixed two-wheel carriage that doubles as the bipod
Mobility
Towed by 4x4 or 6x6 light truck
Variants

Public reference sources describe the UBM-52 family through the base M52 and incremental M52A-series improvements.

VariantConfigurationDesignation notes
M52Base production model

Listed as the basic UBM-52 variant.

Sources: ARMSNET UBM-52

M52A1Incremental improvement

Described as a reduced-weight update with smaller parts and revised materials or hydraulic fluid.

Sources: ARMSNET UBM-52

M52A2Muzzle-system update

Described as using one fewer cylinder with an improved muzzle arrangement.

Sources: ARMSNET UBM-52

M52A3Hydraulic-system update

Described as using revised hydraulic fluid with a fluid-level indicator.

Sources: ARMSNET UBM-52

M52A4Mobility update

Military Periscope identifies the UB M52A4 as a common variant fitted with pneumatic tires.

Sources: Military Periscope UB M52 Overview

Related 120 mm Mortars

The UBM-52 sits in the same Yugoslav and Soviet-pattern 120 mm mortar lineage as several cataloged systems.

Compatible itemItem typeCompatibility evidence
120-PM-38, 120 mm towed heavy mortar, Artillery120-PM-38Soviet-pattern predecessor

WeaponSystems.net notes the Soviet 120 mm PM-38 as the design basis visible behind the UBM-52 lineage.

Sources: WeaponSystems.net UBM-52

PM-43, 120 mm towed heavy mortar, ArtilleryPM-43Related Soviet 120 mm mortar

WeaponSystems.net links the UBM-52 to the broader Soviet 120 mm mortar capability that the Yugoslav design sought to mimic in a lighter format.

Sources: WeaponSystems.net UBM-52

120 mm M74 mortar, 120 mm smoothbore towed mortar, Artillery120 mm M74 mortarLater Yugoslav 120 mm mortar

The M74 is cataloged separately as a later Yugoslav 120 mm mortar family member rather than a UBM-52 subvariant.

Sources: Universal Mortar UB M52

120 mm M75 mortar, 120 mm towed smoothbore mortar, Artillery120 mm M75 mortarLater Yugoslav 120 mm mortar

The M75 is cataloged separately as another later Yugoslav 120 mm mortar family member rather than a UBM-52 subvariant.

Sources: Universal Mortar UB M52

Ammunition Fired

Public reference material describes the UB M52 as a smoothbore 120 mm mortar firing fin-stabilized 120 mm mortar ammunition; individual round compatibility still depends on pressure and launcher qualification.

AmmunitionAmmunition typeFiring evidence
Mortar bombs, 120mm, Heavy mortar ammunition, MunitionsMortar bombs, 120mm120 mm mortar ammunition class

The UB M52 is documented as a 120 mm smoothbore mortar, and reference material lists high-explosive, smoke, illumination, and practice 120 mm mortar bombs among its ammunition types.

Sources: Universal Mortar UB M52

Timeline

120 mm UBM-52 Key Events

  1. Yugoslav service entry

    Reference sources place UBM-52 service entry and production in the early 1950s after 1948-1951 development work.

  2. UB M52 transferred for Otočac defense

    Davor Peitel's HMDCDR-published account records a 120 mm UB M52 with an NSB-1 sight handed over for the defense of Otočac.

Media

120 mm UBM-52 Images

120 mm UBM-52, 120 mm heavy mortar, Artillery - view 1
Source: Wikimedia Commons UB M52 7245
120 mm UBM-52, 120 mm heavy mortar, Artillery - view 2
Source: Wikimedia Commons UB M52A Kalemegdan
Related Weapon Systems
120 mm M75 mortar, 120 mm towed smoothbore mortar, ArtilleryArtillery120 mm M75 mortar120 mm towed smoothbore mortarThe 120 mm M75 mortar is a Yugoslav-designed towed smoothbore mortar associated with the M74/M75 light-mortar family and post-Yugoslav export literature. Yugoimport describes it as infantry close-support artillery for high-angle fire, smoke, illumination, and difficult terrain, while Serbian sources and later defense reporting show the legacy weapon being paired with modern fire-control equipment. Direct records place M75 mortars in JNA fire support around Dubrovnik in 1991 and in Armenian/Artsakh losses during the 2020 Nagorno-Karabakh war.
SOKO G-4 Super Galeb, Advanced jet trainer and light attack aircraft, Aircraft & UAVsAircraft & UAVsSOKO G-4 Super GalebAdvanced jet trainer and light attack aircraftThe SOKO G-4 Super Galeb is a Yugoslav single-engine advanced jet trainer and light attack aircraft built by SOKO in Mostar after development by the Aviation Technical Institute. Designed to move pilots from jet training into light strike tasks, it entered serial production in the early 1980s, remained in Serbian service after Yugoslavia's breakup, and is directly documented in Croatian, Bosnian, and Kosovo War combat or loss records.
120-PM-38, 120 mm towed heavy mortar, ArtilleryArtillery120-PM-38120 mm towed heavy mortarThe 120-PM-38, also known as the M1938, is a Soviet 120 mm smoothbore heavy mortar designed under B. I. Shavyrin and built for infantry fire support. Its large bomb, two-wheel transport arrangement, and roughly 5.7 km range made it a durable regimental mortar design; OSCE monitoring documented PM-38 mortars in Donbas heavy-weapons holding and storage records during the 2014 Russia-Ukraine War, while Oryx listed M-1938 heavy mortars in Yemen's pre-war army inventory.
M-84A4 Sniper, Main battle tank, TanksTanksM-84A4 SniperMain battle tankThe M-84A4 Sniper is a Croatian upgrade of the Yugoslav M-84 main battle tank, itself derived from the Soviet T-72 family. The variant keeps the three-crew, autoloaded 125 mm tank layout while emphasizing improved fire control, day/night sighting, communications, and Croatian M-84 fleet modernization; Croatian officials confirmed M-84 transfers to Ukraine, and Ukrainian 141st Mechanized Brigade crews later appeared with vehicles identified in defense reporting as M-84A4 Snajper tanks during the 2014 Russia-Ukraine War.

Sources

WeaponSystems.net UBM-52Publisher: WeaponSystems.net | Note: Supports UBM-52 identity, Yugoslav origin, Military Technical Institute developer attribution, early-1950s service entry, production timing, aliases, approximate production scale, specifications, carriage, mobility, operator context, and PM-38/PM-43 lineage notes. | Accessed: 2026-07-13ODIN UBM-52Publisher: U.S. Army ODIN | Note: Supports UBM-52 identity as a Yugoslav 120 mm heavy mortar, M1938 lineage, and integral wheeled-carriage design context. | Accessed: 2026-07-13Military Periscope UB M52 OverviewPublisher: Military Periscope | Note: Supports UB M52 design context, carriage-fired layout, recoil-cylinder description, and the UB M52A4 pneumatic-tire variant. | Accessed: 2026-07-13ARMSNET UBM-52Publisher: ARMSNET | Note: Supports UBM-52 designation, PPT Namenska attribution, 120 mm mortar type, towed mobility, core specifications, and M52/M52A1/M52A2/M52A3 variant descriptions; equipment-type metadata is treated cautiously where it conflicts with the mortar description. | Accessed: 2026-07-13Universal Mortar UB M52Publisher: Wikipedia | Note: Used only as baseline terminology and leads for the UB M52 name, development period, service history, variant list, ammunition types, and operator claims; direct conflict use is sourced separately. | Accessed: 2026-07-13Wikimedia Commons UB M52 7242Publisher: Wikimedia Commons | Note: Supports image provenance for the primary UB M52 photograph, including Roberta F. authorship and CC BY-SA 3.0 licensing. | Accessed: 2026-07-13Wikimedia Commons UB M52 7245Publisher: Wikimedia Commons | Note: Supports image provenance for the secondary UB M52 gallery photograph, including Roberta F. authorship and CC BY-SA 3.0 licensing. | Accessed: 2026-07-13Wikimedia Commons UB M52A KalemegdanPublisher: Wikimedia Commons | Note: Supports image provenance for a supplementary UB M52A gallery photograph at Kalemegdan, including Srdjan Popovic authorship and CC BY-SA 3.0 licensing. | Accessed: 2026-07-13Peitel Na prvoj crti protiv smrtiPublisher: Hrvatski memorijalno-dokumentacijski centar Domovinskog rata | Note: Supports direct 1991 Croatian War of Independence context by documenting UB M52 120 mm mortars with Croatian police and ZNG-linked defenders around Otočac, including a September 1991 transfer for Otočac defense. | Accessed: 2026-07-13HMDCDR 2011 ReportPublisher: Hrvatski sabor / Hrvatski memorijalno-dokumentacijski centar Domovinskog rata | Note: Supports publication context for HMDCDR source-material and memoir-series work used for Croatian War source evaluation. | Accessed: 2026-07-13MCIA El Salvador Country HandbookPublisher: U.S. Marine Corps Intelligence Activity | Note: Supports El Salvador inventory context by listing 60 Yugoslav 120 mm UBM-52 mortars, but it is not used as direct conflict-use support. | Accessed: 2026-07-13MCIA Bosnia and Herzegovina Country HandbookPublisher: U.S. Marine Corps Intelligence Activity | Note: Supports postwar Bosnia inventory context by listing Federation Army MB-120-mm UBM-52 mortars in a CSBM-derived equipment table, but it is not used as direct Bosnian War use support. | Accessed: 2026-07-13Balkan Battlegrounds UBM-52 ReferencePublisher: Central Intelligence Agency | Note: Supports Balkan reference context by listing the UBM-52 as a Yugoslav-manufactured 120 mm mortar in a military history reference, but the accessible text does not cleanly assign this mortar to a specific catalog side. | Accessed: 2026-07-13