WTF: The ultimate crazy $40,000 handgun with 30mm grenade launcher.
In appearance, Rico’s Signature Gun is reminiscent of the Holdt R4 Pitbulls from the first Just Cause, albeit larger. In terms of power the weapon exceeds the Pitbulls by far, making it a lethal addition to Rico’s arsenal.
As it stands today, law-abiding Americans who want to drive from Florida to northern New England are confronted by up to 15 different sets of state laws. You can cross a state line in an instant and frequently without warning. Not being able to distinguish between the laws of New Hampshire, New Jersey, and New York can mean the difference between lawful conduct and a twenty-year prison sentence.
Note that the two bullets on the pre-order picture are the .454 magnum cartridge and the 30mm grenade for the underslung launcher. This suggests that this gun can shoot both rounds and indeed the Signature Gun appears to have an underbarrel grenade launcher, but sadly it can only fire the .454 magnum cartridge like a normal pistol/revolver in the game.
It is much more powerful than the standard pistol, and costs as much as a normal revolver, despite this, it is actually weaker than a revolver. It will kill grunts in two shots, though elites still require multiple shots to vanquish. It can fire 6 bullets before a reload and when bought, the gun comes with 90 rounds in total. This equates to just over $444 per round. Bullets for this gun cannot be found throughout the game, so once out of ammo, the gun must be bought.
Source: Just Cause