It seems that there is a new glitch in the recently released Mafia 3 that falls into the crime-adventure genre of games. This newly surfaced aspect also lets players manipulate it to obtain infinite ammo for absolutely free.
Making this discovery public via a YouTube video, a tipster states that players, within Mafia 3 can start by calling-in the arms dealer outside the stadium. Then, walk up to the arms dealer and choose two weapons belonging to the same category.
An example here is, you can choose two rifles, two machine guns and two special weapons. Do ensure to check that both the weapons fall into the same slot.
After you have chosen the weapons, click on the weapon boxes to save the weapons; remember that timing is a key factor here as it ensures that your weapons are saved while you are browsing (between different weapons). Remember to maintain proper time here as trying to save weapons very quickly would result in a no-save condition. Even significant time lapse hinders the ability of auto-saving weapons when you are checking out the different weapon types upon confronting the arms dealer (and his weapon repository).
For instance, you can choose the Hawk 450 Night Vision and the Viper 555 assault rifles and then resort to continually equipping these weapons. You should notice that the weapons spawn. Then, select the weapon you want to keep.
Back-out and turn around. Call the arms dealer again and have him park far away from the stadium. Spawn all the weapons by equipping these continuously as explained above.
After this process, all your chosen weapons (in stacks) are thrown on the road. In this instance, mounds of rifles are generated easily.
Then, test out the weapons by firing bullets in the air. Note that these rifles have fully-loaded magazines. Start firing and reload to get more ammunition.
To test the above glitch, navigate to a different location and call the arms dealer again. Repeat the weapon spawning process. Collect all the "duplicated" weapons and ammo. Test these out. Exhaust all ammo, and then repeat the process of spawning.
Do remember that the unlimited ammo glitch may not work in locations such as tunnels, sewer lines and overpasses. Also do not spawn too many weapons at one time.