Ghost Town Gunfight

 is a quest in Fallout: New Vegas. It involves the town of Goodsprings and a powder gang led by Joe Cobb. You can either save Goodsprings and destroy the Powder Gangers, or side with the Powder Gangers and destroy Goodsprings.

Quick walkthrough
In Goodsprings the Courier is confronted by a group of Powder Gangers who threaten to blow up the town. The Courier may side with the Gangers and help lead the attack against the town, or help the citizens of Goodsprings. If the Courier aims to protect the town, various citizens of Goodsprings can be enlisted in the fight and will offer several bonuses, such as the use of dynamite courtesy of Easy Pete and a supply of armor and weapons from Chet. Sunny Smiles and the other recruits will then help the Courier in ridding the town of the Gangers. Whomever the Courier chooses to help can be controlled with the companion wheel.

Detailed walkthrough
The quest starts after overhearing Trudy arguing with Joe Cobb, and questioning her about the argument, or after Mitchell mentions an issue in the town of Goodsprings.

For the optional quests to get the town of Goodsprings against the Powder Gangers, many of them will need convincing. This is achievable by using the magazines scattered throughout the town to help. Chet has Salesman Weekly the mag needed to get Barter +10 to convince him. The other required mag will help you convince Easy Pete to use his dynamite. This mag is the Patriot's Cookbook, and can be sometimes found in the mailbox outside of Doc Mitchell's house, the mailbox outside of the ruined house in the northeast corner of Goodsprings, or inside a cell in Cell Block A, in the NCR Correction Facility. Although, the last one need to be stolen. To convince Trudy to join in, use the Meeting People to get +10 Speech. You can also enlist Victor to join your side in the fight but fails to show up. When talking him about this you will find that he was shutdown by an unknown person to keep him from fighting.

Once the citizens of Goodsprings have been convinced to help join the fight, speak with Ringo, who is hiding out in the Goodsprings Gas Station, and Trudy will interrupt with the notice that the Powder Gangers have arrived. The battle will begin.

Bugs

 * The skill magazine Patriot's Cookbook which can help convince Easy Pete may not be in the mailbox outside of Doctor Mitchell's house. Other mailboxes in town have a chance of spawning the magazine; alternatively, you can reload the game and try again. (confirmed on Xbox360)