u/DependentWaste3764

Step 1: Make sure you have to weapon you want infinite ammo on equipped (in this case requiem)

Step 2: Move out any gun and then move out Requiem

Step 3: Move the gun back in and then Requiem

Step 4: Unequip the gun, close the inventory and quickly open it again

Step 5: Equip Requiem and close the inventory

You'll know you did it right if the crosshair doesn't appear. It'll reset during cutscenes or when taking blood