Here is the full list of all 26 Call of Juarez: Gunslinger achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Complete the duel challenge, winning all duels honorably.
Forgive your lifetime nemesis.
Complete the Story on True West difficulty.
Kill your lifetime nemesis honorably in a duel.
Collect all Nuggets of Truth.
Get all Arcade Mode stars.
Complete all Arcade missions.
Kill a bird during a winning duel.
Win a duel honorably in under 0.6s.
Shoot a flying stick of dynamite and the one who threw it on a single Concentration.
Unlock all skills in Story Mode.
Complete the Story on hard difficulty.
Complete the Story on any difficulty.
Find and kill Jim Reed.
Discover a shipwreck in the Missouri swamps.
Kill a shotgunner with a close-range shotgun blast.
Fight in Concentration for 15 minutes.
Score the maximum of 3 stars in any Arcade mission.
Reach combo level of 20.
Find all Nuggets of Truth in a single mission.
Unlock both exclusive weapons in a single category of skills in Story Mode.
Kill 5 enemies when falling down through the air.
Find and kill Johnny Ringo.
Shoot through a hole to kill an enemy that hides behind a shield.
Give it to them straight about your meeting with Pat Garrett.
Unlock a skill.