rare guns

I can tell you the locations but not where to find them at exactly. You can find Lincoln's Repeater at the Museum of History. Ol' Painless is at the Republic of Dave and it's in his safe. The Terrible Shotgun is at Evergreen Hills, Smiling Jack has it.

There's actually about 90 unique weapons and outfits in Fallout 3, so take the time to try and find them, some of them are better than the normal counterparts while others are worse, it just depends on what they are. But I'll be able to help you on this.

Lincoln's Repeater: Found in the Museum of History destination in one of the offices in the rear of the archives section. You'll find it in the display case. So check your map and get to the Archives door.

Ol' Painless Hunting Rifle: The Republic of Dave, Dave is actually carrying it unless he's asleep, and then it's in his safe. So sneak in and pick the safe and grab the rifle or kill him for the Miscellaneous quest You Gotta Some 'Em In The Head from Mr. Crowley in Underworld and take his key along with the rifle. Terrible Shotgun: Evergreen Mills, go inside the building in Evergreen Mills and take the left path and you'll enter the Bazaar and you'll be able to take a right path, go down a hill and you'll find a trader named Jack. Go ahead and kill him even though he tells you that you don't need to and you can loot his entire inventory along with the shotgun. Best shotgun in the game, in my opinion.

If you're looking for better weapons as well, find the Xuanlong Assault Rifle, Victory Sniper Rifle, Vengeance Gatling Laser, Firelance Alien Blaster, Smuggler's End Laser Pistol, The Kneecapper Sawed-Off Shotgun, Experimental MIRV Fat Man. There's a whole bunch of stuff you can find, like I said there's 90 or so outfits or weapons that you can find within the game.

Good luck with the search.

There is a trader at evergreen mills named lucky [i think that's his name] who carries the terrible shotgun Lincolns repeater is in a display case in the museum of history and president Dave in the republic of Dave carries ol painless