Search the indicated locations to find all unique weapons:
.357 Magnum Revolver - Lucky: In Primm at The Bison Steve Hotel, in a floor safe (requires 75 Lockpick skill level) behind the cash register of the Gift Shop (northeast room).
.44 Magnum Revolver - Mysterious Magnum: Owned by the Lonesome Drifter, by the Sunset Sasparilla Billboard, close to El Dorado Dry Lake.
9 Iron - Nephi's Golf Driver: Carried by a Fiend named Driver Nephi, in his territory.
9mm Pistol - Maria: On Benny, when you kill him.
9mm Submachine Gun - Vance's Submachine Gun: In Win's Hideout, inside the safe.
Alien Blaster: Locate the large spaceship north and a little east of Horowitz Farmstead (east of Brooks Tumbleweed Ranch), then kill the Alien Captain. Note: Wild Wastleland trait is required.
BB Gun - Abilene Kid LE BB Gun: Inside the Fiend's Shack, lying on a shelf.
Bladed Gauntlet - Cram Opener: In Camp McCarran, owned by Little Buster.
Boxing Gloves - Golden Gloves: Inside Lucky 38 Casino, on the upper bar of the casino floor.
Bumper Sword - Blade Of The East: In Legate's Camp, carried by Legate Lanius.
Cleaver - Chopper: On the stove of Wolfhorn Ranch.
Combat Knife - Chance’s Knife: In Chance's Grave.
Cowboy Repeater - La Longue Carabine: In Camp McCarran, carried by Corporal Sterling, whom you must kill to get it.
Displacer Glove - Pushy: Inside the Ruby Hill Mine, on the body of a Jackal Gang member.
DogTag Fist - Recompense Of The Fallen: In Aurelius' desk, on the upper floor of the main building in Cottonwood Cove.
Euclid's C-Finder: On the Freeside Streets, carried by Max, in and around Nick and Ralph's.
Fat Man: In Quarry Junction, near the skeleton by the southern silt pool. It is also occasionally found on prospector corpses.
Fire Axe - Knock Knock: In the Camp Searchlight Fire Station, in the restrooms.
Frag Grenade - Holy Frag Grenade: In Camp Searchlight, in the basement of the eastern church. Note: Wild Wastleland trait is required.
Gauss Rifle - YCS/186: At the Mercenary Camp; Wild Wasteland trait must not be taken.
Grenade Machine-gun - Mercy: On the floor of Dead Wind Cavern, near a dead BoS Paladin.
Grenade Rifle - Thump-Thump: At the Nellis Array, lying on the floor near the Ant mound.
Hunting Shotgun - Dinner Bell: At The Thorn, in the sewers in front of Westside. You must complete the "Bleed Me Dry" quest given by Red Lucy.
Laser Pistol - Pew Pew: After completing "The Legend Of The Star" quest, it will be on the body of Allen Marks.
Laser Rifle - AER14 Prototype: Inside the Vault 22 Common Area, on the blocked stairwell only accessible from the fifth level (Pest Control).
Lead Pipe - The Humble Cudgel: Inside the Sealed Sewers, near the Prospector Corpse.
Machete - Liberator: In Nelson, carried by Dead Sea.
Minigun - CZ57 Avenger: In the Devil's Throat, inside, at the back of the container trailer, by the dead body.
Missile Launcher - Annabelle: In Black Rock Mountain, carried by the Nightkin Sniper on Black Rock Summit, whom you must kill to get it.
Marksman Carbine - All-American: In the Armory Cache, Vault 34, on the floor, on an upturned table.
Oh, Baby!: In the deepest part of Charleston Cave, near a Chewed Stealth Boy.
Plasma Rifle - Q-35 Matter Modulator: In the locked shipping room of REPCONN HQ, in a pod casement.
Pulse Gun: In the Armory Cache, Vault 34.
Sawed-Off Shotgun - Big Boomer: In Gibson Scrap Yard, carried by Old Lady Gibson, whom you must kill to get it.
Sniper Rifle - Gobi Campaign Scout Rifle: In the footlocker of the Sniper's Nest, overlooking the Cottonwood Cove.
Spiked Knuckles - Love and Hate: In Bonnie Springs, on the Viper Gang Leader.
Straight Razor - Figaro: In the back of King's School Of Impersonation, owned by Sergio, whom you must kill to get it.
Tesla Cannon - Tesla-Beaton Prototype: On the ground near the crashed Vertibird.
That Gun: In Novac, on a shelf in the locked storage room inside the Dino Bite Gift Shop.
This Machine: At the end of the "Dealing With Contreras" quest, it will be a reward from Contreras for not turning him in.
Varmint Rifle - Ratslayer: Inside the Broc Flower Cave, propped up against the desk.
Zap Glove - Paladin Toaster: In Black Rock Cave, near the body of the dead prospector.