We all know the M163 vulcan, 20mm gatling on an a M113 chassis.I'm surprised nobody has taken the gun/turret and mounted it on a two wheel trailer, the US army designation is the M167.When in the firing position the weapon sits on three outriggers to provide a more stable base.If this weapon could be carried under a blackhawk, or towed behind a truck in OFP that would provide some great firepower.I've seen pics of a protoype which also packs stinger missiles, four I think.