Fleeting Joy

As soon as the mission starts, follow Sadie out the back of the house. You'll need to go through to another house using a trap door.

After a quick cutscene, you'll be thrown into Dead Eye. Your first objective here is to get at least two headshots. The Gatling Gun user is a high priority, so make sure they're one of your targets. You'll have enough time to tag everyone, but focus on that Gatling Gunner.

Once that Dead Eye sequence is over, the main shootout begins. Take cover immediately and start returning fire. For the Gold Medal, the accuracy requirement is only checked at the very end, so don't stress too much about where you're hitting right now, just focus on taking down those Pinkertons.

Stick with Sadie and Bill as you move north. Keep using cover whenever you can and pick off the Pinkertons. Remember, you can't use any health items during this mission, and there are a lot of enemies, so keeping Arthur alive is key.

After you clear out the Pinkertons hiding in the trees, Sadie will tell you to hop onto the Gatling Gun. This is where the Gold Medal gets a bit tricky.

While on the Gatling Gun, you need to score at least five headshots and maintain 70% accuracy. It's super easy to just hold down the trigger, but don't do that! Fire in short bursts and aim for the head. You'll be facing enemies in front of you and to your left, so keep an eye on the radar and listen to Sadie and Bill for callouts. Ignore those red canisters; shooting them will hurt your accuracy.