This trick requires the dual handguns, all weapon slots full, and at least one bullet for the dual handguns. Have the dual handguns equipped, and find a weapon you do not have in your inventory. This weapon must be on the floor, not leaning or on top of something. Hold Square to switch out the dual handguns for the new weapon, then switch back for one handgun and grab the other. You will notice that you have more handgun ammo. For example, if you had one bullet for both and you used this trick, you should now have two bullets. If you repeat the trick, it will increase to 4 then 8, 16, 32, 64, 128, then the maximum of 200.
