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Milkor Mk-4 UBGL

40mm Single-Shot Under-Barrel Grenade Launcher [ 2009 ]

The Milkor Mk-4 UBGL 40mm under-barrel grenade launcher immediately transforms the basic infantryman into a formidable grenadier.

Authored By: Staff Writer | Last Edited: 08/15/2018 | Content ©www.MilitaryFactory.com | The following text is exclusive to this site.

With a long-running history in design, development and production of excellent grenade launchers, Milkor Pty Ltd of South Africa took their expertise to the under-barrel launcher market resulting in the 40mm Mk-4 UBGL ("Under-Barrel Grenade Launcher"). Due to the entrenched nature of certain automatic rifles such as the American Colt M16, Heckler & Koch G3 and Soviet/Russian AK-47 types, the UBGL was specifically designed to adapt to these in-play systems. The Mk-4 can, therefore, connect to such assault weapons by way of a Picatinny or STANAG-style accessories rail or even more custom-made attaching solutions. The UBGL was introduced into the Milkor company line up in 2006.

The ability for a modern warfighter to integrate a grenade-launching solution is second to none, turning the standard infantryman into his own fire support grenadier. The under-barrel nature of such launching systems keeps the host weapon's dimensions in check, the attacked launcher utilizing the existing magazine as a grip handle. The Mk-4 features a cylindrical appearance tapering towards the muzzle. The mounting gear is along the top and fits under the host weapon's handguard in the typical way. Loading/reloading requires the frontal section of the launcher to be swung out to expose the breech. The UBGL is regarded as a lightweight design, adding little to the weight of an existing, fully-loaded weapon. The barrel is made of steel for robustness and wear and is internally rifled for accuracy. The system makes use of the widely-accepted low-velocity 40mm grenade. These grenades are further offered in various payload/warhead types spanning lethal, non-lethal and tactical breeds. The entire Mk-4 device can be quickly removed if need be by management of a simple release clip. The weapon can also be fired as a standalone system if required.

Due to the engagement nature of grenade launchers, the Mk-4 if given a minimum listed range as well as a maximum range for operator safety. The minimum range is listed at 30 meters with an effective range out to 250 meters though 350 meters is possible under certain circumstances. A trained/experienced operator can sustain a rate-of-fire of six rounds per minute. Sighting is though a saddle sighting device though a ladder and aim point system can also be utilized.


Service Year

South Africa national flag graphic
South Africa


40mm Single-Shot Under-Barrel Grenade Launcher

Milkor Pty Ltd - South Africa
(View other Arms-Related Manufacturers)
National flag of South Africa South Africa
(OPERATORS list includes past, present, and future operators when applicable)
Fire Support
Capable of suppressing enemy elements at range through direct or in-direct fire.

Overall Length
240 mm
9.45 in
Barrel Length
240 mm
9.45 in
Empty Wgt
2.09 lb
0.95 kg

Saddle Sight; Ladder Sight; Aim Point


Single-Shot; Reusable

(Material presented above is for historical and entertainment value and should not be construed as usable for hardware restoration, maintenance, or general operation - always consult official manufacturer sources for such information)



Rounds / Feed

Single-Shot; Reusable
Cartridge relative size chart
*May not represent an exhuastive list; calibers are model-specific dependent, always consult official manufacturer sources.
**Graphics not to actual size; not all cartridges may be represented visually; graphics intended for general reference only.
Max Eff.Range
820 ft
(250 m | 273 yd)

Mk-4 UBGL - Base Series Designation

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Image courtesy of Milkor Pty Ltd marketing material; Used with permission.


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