Red dead revolver 100% completion + all difficulties done
3For 100% you need:
All main missions done with excellent rating (3/4 stars)
Bounty hunter mode done
Buy everything from the stores in brimstone (bar, bank, clothing, weapons, general store) you are going to have to do a second walkthrough for this and I recommend doing it on hard so you unlock the remaining difficulties
Unlock Manny Quinn in showdown mode (burn yourself for 6 minutes straight in showdown mode)
There are also some secret buys you need to get for 100% I’ll list them up here:
After the Rogue Valley chapter, you visit Brimstone for the third time and if you talk to Jack for a couple of times he sells you a health upgrade called Lucky Flask for $1500.
After the Ghost Town chapter, you visit Brimstone for the fourth time and if you talk to Paperboy for a couple of times he sells you a dead eye upgrade called Pocket Watch for $1500.
Saloon Fight chapter also has a health upgrade in upstairs. Talk to the girls relaxing in bath tub and buy Hot Bath for $1500.
At the beginning of the Jailbreak chapter, turn behind and talk to that "corpse" laying there. He sells you a Horseshoe for $1050 that unlocks a Showdown character and a weapon - Snake Oil for $400.
After you liberate the girl from her cell, talk to her a couple of times and she will sell you a Kiss for $1 which is another health upgrade.