Wikia

Players who are hoping to use firearms more than their current ammo will allow will find this useful.

The pistol ammo recipe is located in the Police Station, after you enter and go up the stairs, take a right and break into the locked room with the Thug inside, the pistol ammo recipe is on the table to the left of the workbench. The recipe requires 2 Metal Scrap and 1 Bleach, making 10 rounds of pistol ammunition.