Speak to Lenny in the camp after completing An Honest Mistake to begin this mission. You’ll need to be quick and accurate with a rifle if you want the Gold Medal here.
Ride with Lenny to the marker, an old civil war battlefield and make your way to the Abandoned Church. Examine it with Arthur to sketch it into his journal and then follow the wagon that passes by to reach the old plantation house Lenny remarked about earlier. Leave the horses in the trees and grab the Rolling Block Rifle before heading to the nearby entrance to take cover. You’ll have an option on how you want this battle to begin, either by shooting the Dynamite or sending Lenny in to create a distraction, go with the distraction.
Once Lenny has drawn a few of the Raiders out, take aim with your rifle and begin shooting. In the shootout you’ll need to make sure that you’re accurate and quick, you only have 11 minutes 30 seconds to complete the entire mission. Make use of Dead Eye while aiming down the scope to line up headshots easier and keep a close eye on the radar to spot any Raiders that may make their way out to your position.
Halfway through the battle, one of the Raiders will make their way onto the balcony of the house and use the Gatling gun, take aim and kill him at all costs to avoid heavy damage. Once the entire area is clear of enemies, head over to the cart in the courtyard and examine the back of it to discover some new rifles. Board the wagon and begin your journey back to the camp when you’re approached by three more mounted Raiders. Quickly activate Dead Eye and take the three Raiders out before quickly galloping back to Camp to complete the mission.