User blog comment:Plexioth- xD/Monster Hunter 3 Ultimate/@comment-208.104.232.97-20120319042027/@comment-58.169.108.90-20120319054917

Depends what you mean by highest raw. The highest number for the raw value as shown in the game is 1508 (there might be higher out there, but I haven't seen it), which both the Uragaan and Uragaan Subspecies' hammers have. This is equivalent to 290 in P3rd's formula (the "true" raw value). Several weapons have higher raw than this, such as the Black Diablos Great Sword, which has 310 raw (it's just shown as lower in game (1488) due to different damage multipliers).

So if you were wondering which has the highest number shown for raw, it's the Uragaan hammers, with 1508. For the highest actual raw, it's probably some bow/bowgun (I can't remember the class modifiers for them, so I'm just guessing based on P3rd.