Here is the full list of all 38 Hard West 2 achievements.
Form sets of Royal Flush with 4 posse at the same time.
Form sets of Full House with 4 posse at the same time.
Collected every card in the game.
Completed a mission using only Shotguns.
Form sets of Straight with 4 posse at the same time.
Completed a mission using only Rifles.
Maxed out loyalty with Lazarus.
Maxed out loyalty with Laughing Deer.
Completed a mission using only Melee weapons.
Completed a mission using only Handguns.
Finish "Daredevils" in no more than 8 turns with all objectives completed.
Finished the game on the Easy difficulty.
Finished the game on the Hard difficulty.
Finished the game on the Nightmare+ difficulty.
Finished the game on the Normal difficulty.
Finished the game on the Nightmare difficulty.
Completed all world map side objectives in Chapter 3.
Finish "One Last Ride" in no more than 12 rounds with all objectives completed.
Killed 60 Hellspawns.
Finish "The Great Train Heist" in no more than 10 turns with all objectives completed.
Finish "Riftwalkers" in no more than 10 turns with all objectives completed.
Finish "Wanted: Lady Shrike" in no more than 15 turns with all objectives completed.
Killed 666 enemies.
Finish "A Plague Upon This Land" in no more than 12 rounds with all objectives completed.
Finish "3:10 To Heaven" in no more than 1 round with all objectives completed.
Maxed out loyalty with Clalish.
Completed all world map side objectives in Chapter 1.
Killed 50 Shadow Dancers.
Finish "Flynn's Vision" in no more than 10 turns with all objectives completed.
Finish "O'Kane Farm" in no more than 8 turns with all objectives completed.
Finish "Frostbitten in Calla Calla" in no more than 10 turns with all objectives completed.
Killed 80 Revenants.
Finish "Blasting Out" in no more than 8 turns with all objectives completed.
Killed 100 Bandits.
Finish "Fooling The Hangman" in no more than 4 turns with all objectives completed.
Maxed out loyalty with Flynn.
Maxed out loyalty with Old Man Bill.
Visited every location in all Chapters.