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.
Win a duel honorably in under 0.6s.
Complete all Arcade missions.
Get all Arcade Mode stars.
Score the maximum of 3 stars in any Arcade mission.
Fight in Concentration for 15 minutes.
Complete the Story on True West difficulty.
Kill your lifetime nemesis honorably in a duel.
Unlock all skills in Story Mode.
Kill a bird during a winning duel.
Complete the Story on hard difficulty.
Complete the Story on any difficulty.
Forgive your lifetime nemesis.
Collect all Nuggets of Truth.
Find and kill Jim Reed.
Reach combo level of 20.
Discover a shipwreck in the Missouri swamps.
Kill a shotgunner with a close-range shotgun blast.
Unlock both exclusive weapons in a single category of skills in Story Mode.
Shoot a flying stick of dynamite and the one who threw it on a single Concentration.
Kill 5 enemies when falling down through the air.
Find and kill Johnny Ringo.
Find all Nuggets of Truth in a single mission.
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.