The GMG (Granatmaschinengewehr or "grenade machine gun") is an automatic grenade launcher developed by Heckler & Koch for the German Army. It is also often referred to as GMW or GraMaWa (Granatmaschinenwaffe). It fires 40 mm grenades at a rate of about 340 rounds per minute. The GMG is belt-fed and can be loaded from either side, making it easy to mount on most platforms. With a variety of day and night sights available, the GMG can be used for most medium-range infantry support situations.
The weapon is 1.09 m long and has a 415 mm rifled barrel; the ammunition box has dimensions of 470x160x250 mm. The gun operates on a recoil-operated blowback basis. It weighs 29 kg; the tripod is an additional 11 kg.
For the NZ Army, the GMG will be equipped with the Vinghog Fire Control System (FCS) to provide the capability for deliberately planned fires, the BAE Heavy Weapon Thermal Sight, and day sights. To support this introduction, the NZ Army has also purchased a combination weapon mount that will fit both the Grenade and Heavy Machine Guns. The weapons are being acquired, with NZ delivery due to start from April 2012 year, and the introduction to service and issuing to units planned to occur in the last quarter of 2012. Within New Zealand, the GMGs will be issued to NZ Army’s two Regular Force Infantry Battalions and Queen Alexandra’s Mounted Rifles (NZ LAV). To support the GMGs’ full introduction in early 2013, a dedicated tactical simulation training system will be acquired this year. Training on the use of the weapon will be conducted at the unit level, with specialist command training being conducted at the NZ Army Combat School as an additional module on existing courses. Training for maintainers will be conducted through the NZ Army Trade Training School. The GMG will complement two other direct-fire weapon systems: the Javelin Medium-Range Anti-Armour Weapon and the FN Herstal .50 calibre Heavy Machine Gun.

▪️ 🛠 Manufacturer Heckler & Koch
▪️ ✅ Produced 1996
▪️ ⬇️ Mass 28.8 kg Gun, 10.7 kg tripod and 8 kg soft mount.
▪️ 📏 Length 1090 mm
▪️ ➡️ Barrel length 415 mm
▪️ ↔️ Width 226 mm (without ammunition box)
▪️ ↕️ Height 208 mm
▪️ ⏫ Cartridge 40x53 mm
▪️ 🔁 Action API Blowback
▪️ ⏩ Rate of fire 350 rounds/min
▪️ ⏭ Muzzle velocity 241 m/s
▪️ 🔝 Effective firing range 1500 m
▪️ ⏏️ Maximum firing range 2200 m
▪️ ⏬ Feed system 32-round disintegrating, closed-link belt
▪️ ⏺ Sights Reflex sight and back-up leaf sight

Ref: Wikipedia; nzdf.mil.nz.