Warp to the 'LR' icon in the town of 'Chuparosa' where you'll meet up with the cool character Landon. Landon wants to teach you how to shoot better after your run in with the locals, so follow him to the back of the town where he's laid up three bottles in the distance.
Use the new Schofield Revolver he gives you as a gift to enter Dead Eye and swipe your gun over all three bottles to auto-target them all. Now watch out for the flock of birds sitting on the roof and get ready to initiate Dead Eye again when Landon startles them with his gun.
You can quickly enter it as they're close together; making shooting down the required two birds much easier than if they were further away. Follow Mr. Ricketts into town and then ride out to help the bank cart that's under threat.
Shoot the two gunmen as you approach them and then it's much safer to use a spot of Dead Eye to line up a silky headshot on the hostage taker. You're not finished yet, as you also need to escort the cart back to town with the help of Ricketts.
It'll come under fire (so deal with them using your rifle here) and when the roadblock shows up, target the lanterns on their carriage to blow it sky high! Once the wagon hits town, the mission will be completed.