Please bear in mind that stats can differ per player based on your stats and gear, make sure to sim yourself.
Single Target Stat Priority:
Mastery > Haste > Critical Strike > Versatility
Multi-Target Stat Priority:
Mastery > Critical Strike > Versatility > Haste
Mastery: Your mastery is called Sniper Training, granting you increased damage on all your abilities and increases your maximum shot range.
Haste: Increasing your auto attack speed, increasing your focus regeneration and reducing the cooldown on your Aimed Shot ability.
Critical Strike: Increasing your chance to critically hit with all spells and abilities.
Versatility: Increasing all your damage and healing done, also decreases all damage taken.
The best way to calculate stat priorities for your character is to "sim" your characterFind out how to sim
Troll > Mag’har Orc > Goblin > Pandaren > Highmountain Tauren > Undead > Zandalari Troll (Pa’ku) > Orc > Tauren > Zandalari Troll (Kimbul) > Blood Elf > Zandalari Troll (Bwonsamdi) > Nightborne
Human > Gnome > Void Elf > Night Elf (Night) > Kul Tiran > Pandaren > Lightforged Draenei > Dwarf > Night Elf (Day) > Worgen > Dark Iron Dwarf > Draenei
Low item level weapon: Incendiary Ammunition
400+ item level: Enchant Weapon - Masterful Navigation
Multi-Target/Mythic+: Enchant Weapon - Masterful Navigation
Gems: Masterful Tidal Amethyst
Pots: Battle Potion of Agility
Flask: Flask of the Currents
Health pots: Coastal Healing Potion