Talk:Weapons/@comment-50.175.52.16-20160220000325/@comment-25669516-20160220091834

If you're running out of ammo while in single player you'll automatically see an option to buy it towards the left corner of your screen. Alternatively, go to the very last section of the shop and scroll to the very end of the list. You'll see all ammo there and you can buy whatever you want according to your weapon.