The Ultimax U-100 MK5 is a Singapore-made 5.56mm light machine gun, developed by the Chartered Industries of Singapore (CIS, now ST Kinetics). The MK 5 variant is an updated version of the MK 4, which was developed for the USMC's Infantry Automatic Rifle competition; the Ultimax lost to the HK's M416-based M27.
The Stubby or Potato grips further increase accuracy in full-auto, while the Ergo and Vertical grips help with mobility. Using a Angled or Folding grip completely cancels out the first-shot multiplier on the U-100 MK5, enabling accurate tap-fire and tight shot grouping in short bursts.
The heavy barrel can be added to add much accuracy to this weapon, but recoil becomes an almost major problem.
If iron sights are used in multiplayer, a rendering bug may occur whereas the sights do not show up for a few brief moments in a similar fashion the F2000 bug in the Battlefield 3 co-op mission The Eleventh Hour.