Weapons in Undead Nightmare

The weapons in Undead Nightmare are mostly the same as in Red Dead Redemption, with a few exceptions.

Repeaters

 * Repeater Carbine - Acquired by clearing the Blackwater graveyard in "Curious Tales from Blackwater",
 * Winchester Repeater - Aacquired during the Survivor mission "Paternal Pride".
 * Henry Repeater - Acquried by saving Nosalida
 * Evans Repeater - Acquired by completing Undead Hunter - Rank 5.

Revolvers

 * Cattleman Revolver - Acquired from the start
 * Schofield Revolver - Acquired by saving Chuparosa
 * Double-action Revolver - Acquired by saving Tesoro Azul
 * LeMat Revolver - Acquired by completing Undead Hunter - Rank 5.

Pistols

 * Volcanic Pistol - Acquired by saving Twin Rocks
 * Semi-automatic Pistol - Acquired by completing "Missing Souls".
 * High Power Pistol - Acquired by completing the doctor random encounter 4-6 times.
 * Mauser Pistol - Acquired by completing Undead Sharpshooter - Rank 5.

Rifles

 * Springfield Rifle - Acquired by saving Ridgewood Farm
 * Bolt Action Rifle - Acquired by saving Cochinay
 * Buffalo Rifle - Acquired by saving Escalera

Sniper Rifles

 * Rolling Block Rifle - Acquired by saving Pacific Union Railroad Camp
 * Carcano Rifle - Acquired by completing Undead Sharpshooter - Rank 5.
 * Explosive Rifle - Acquired by saving Rathskeller Fork.

Shotguns

 * Double-barreled Shotgun - Acquired from the start
 * Sawed-off Shotgun - Acquired during the Survivor mission "Dinner for Two".
 * Pump-action Shotgun - Acquired by saving Torquemada.
 * Semi-auto Shotgun - Acquired during the undead pile random encounter.

Thrown Weapons

 * Tomahawk - Acquired by saving Manzanita Post
 * Fire Bottle - Acquired by saving Thieves' Landing
 * Dynamite - Acquired by saving Gaptooth Breach
 * Undead Bait - Acquired during the mission "A Cure for Most of What Ails You".
 * Boom Bait - Acquired by completing the Survivor mission "Biographies and Lies".
 * Holy Water - Acquired during the mission "Mother Superior Blues".

Melee Weapons

 * Torch - Acquired during the mission "Curious Tales from Blackwater".