Cheat mode
Enter "ROCKSTAR" as a name. Press [Start]
to pause game play and enable the "Invulnerability"
option. Press [Left] or [Right] at the mission selection
screen to choose any mission and phase.
255 ammunition reloads
Kill your partner and take his gun. Waste one gun's
ammunition until it is at "0/0". Then, use the other
gun until he reloads. While he reloads, switch guns and he will
reload the other gun to "0/255".