This article describes a feature in the first Apocalypse Rising
The Forward Grip is an under barrel attachment that is found in Apocalypse Rising. It is used as a recoil reducer for weapons. It increases precision levels on the weapons that can use it by 20%. The Forward Grip is ideal for sharpshooters who are looking for a more precise and accurate shot when firing at a distance. The attachment is also useful on automatic weapons, reducing the climb on ADS. The item is commonly found in Military Tents and at Helicopter Crash Sites and any other location with a military spawn point.
While this is an underbarrel attachment, you can not attach it to the M9 or the G18.