348 million, 1908 kills, version 3.5i.
http://ec2-1.playr.co.uk/onslaught/i...hp?view=103952
This game is about combinations, not guns.
To get your combination to fire properly, it may be important to ensure that some of the involved guns can't see the path.
Nukes (RBB) can kill 3 enemy in a row on a straight road by hitting the lead, so 4 nukes can clear a wave. Nukes fire 2.5 times per wave (more in some past versions), so 1 tried building 3 RBB combinations. The power is affected by the damage multipliers.
Recent version changes have affected the power of nukes.