Westerado: Double Barreled

To get this achievement (and unlock the indian as a playable character) you need to help the indians take over Clintville. I'd recommend doing this on a fresh savefile. It'll just take a few minutes anyways.

First you need to find the Indian Outpost (northeast of Clintville) and talk to the indian chief. Avoid accusing the indians of anything and then offer your help.

You'll get a mission to free three buffalo herds to gain the chief's trust. There are five herds in the game:
- Rancher in the north part of Clintville
- Rancher Bob's farm (northwest of Clintville)
- Rancher Cobb's farm (south of Clintville)
- Rancher Richard's farm (southeast of Clintville)
- The military fort (southeast of Clintville)

Just shoot the lock off the gate and herd all of the buffalo out of the pen. If you free all of them you'll also get Once you've freed three herds, return to the Outpost and talk to the chief. Offer your help again and he'll ask for assistance attacking the military fort. Head into the mines and follow the map eastward towards the exclamation mark on the map. When you reach the indian outpost, speak to the indian outside the big tipi up top and tell him the chief sent you. Head south towards the fort and get ready for a fight.

Before the fight I'd recommend you make a visit to the store in Clintville and steal the rifle, which shoots through anything, it's massively useful at fighting an army.

Defeating the army and talking to the chief inside the fort will net you a tomahawk (unique weapon) and Offer your help again and this time you'll have to attack Clintville. With the huge rifle at hand this fight shouldn't be too hard. If you find yourself cornered you can also step off and let your allies fight for you, they are quite capable.

Winning the fight and talking to the chief will net you a feather (unique hat) and the achievement!