Here is the full list of all 21 Western 1849 Reloaded achievements.
Complete insane difficulty
Kill 100 bandits using dynamite
Fire 5000 bullets
Complete very hard difficulty
Kill 25 bandits in Rage Mode
Kill 2000 Bandits
Knock down 250 hats from bandits
Perform 500 perfect reloads
Complete hard difficulty
Have 2 items equipped in the backpack
Shoot 50 canns
Perform 500 head shots
Perform a 15 kill streak
Complete medium difficulty
Fire 100 bullets in one game
Perform 50 headshots in one game
Complete 3 waves in a row without losing any health
Perform 50 Perfect Reloads in one game
Upgrade your equipment 3 times
Complete easy difficulty
Kill 6 bandits with one clip