Sling of accuracy is the improved version of slings; in particular, they receive an average 5 point bonus to hit compared to generic slings. They also get +2 range for attacks using bullets/rocks/crystals. While it is also possible to use potions with slings, their range is not affected by slings of the long shot; base range of potion thrown either by sling or by hand is 3 tiles (though slings can receive further bonuses through skill marks and talents like Proficiency with slings).