In the 2000s the US tried to get a modular OICW air-burst rifle into production by teaming Alliant Techsystems with HK. The result was called the HK Smartrifle/XM-29 and was slated to begin service with US forces in 2006- never happened. Cost overrruns and individual unit cost climbed. Weapon was heavy and bulky. But in S Korea Daewoo decided to make their version which combines a 5.56mm standard assault rifle component UNDER with a TOP 20mm air-burst grenade launcher and on top of that is the EFCU (Electronic Fire Control Unit). Weight is 13.5 lbs and cost is $14,000 per unit which is reasonable for this time. Unlike the US, the S Koreans are selling them for export while producing batches of them in intervals for the ROK Army. The lower component is fed by 20 or 30 rd box mags while the GL is fed from a large box-type 6 rd mag to the rear. The EFCU has a laser rangefinder, ballistic computer, and day & night vision. GL rounds can impact directly light armor or can be fused to air-burst to take out soldiers in ditches, trenches, behind walls, etc... with devastating effect. S Korea exported 40 to UAE and then produced a similar amount for ROK forces. But of the 20 sent to Afghanistan, 7 malfunctioned and the rest had an almost 50% defect level with all 3 components!!!! So, Daewoo was ordered to fix the defects and that's where they are now just 2 years into operational service. It is ironic that the German/US weapon was too complex and good for service while the S Korean version is more simplified and yet malfunctioning, causing a reliability problem! It is however the first air-burst rifle in active service anywhere in the world. S Korea is a leader in micro-electronics, but adding that EFCU to a questionable modular combat rifle under battlefield conditions has proven difficult.

K-11: http://world.guns.ru/userfiles/images/assault/as98/xk11_1.jpg