A SwissSIG-Sauer 14mm handgun rechambered for 12.7mm ammunition, likely designed for long-range pistol hunting or target shooting. It was imported to the United States from the European Commonwealth before the war. They were decently common early on in the survivor era, but the number of working units has swiftly declined.
The 12.7mm fires and reloads like a 9mm, but packs a more serious punch. This pistol has the second highest base damage-per-second of any non-energy pistol in Fallout: New Vegas, bested only by A Light Shining in Darkness. It takes a Gunsskill of 75 and a Strength of 7 in order to take full advantage of the weapon. Its only drawback is its rather poor accuracy as it has the highest weapon spread of any pistol in the game, comparable to even some automatic weapons.
The 12.7mm pistol has the same durability as the less powerful 10mm pistol; it can fire a total of about 395 standard rounds, the equivalent of 57 reloads, from full condition before breaking.
Bloodborne Cave - There is one in the chamber just after the Legendary Nightstalker.
The silencer modification makes possibly the most noise of any silenced weapon due to its large caliber, realistically the target or targets would still hear the shot, however the game recognizes it as a fully silenced weapon therefore the player can fire and still remain undetected
Behind the scenes
It is modeled after the 14mm pistol From both Fallout 1 and Fallout 2, the only difference being the magazine does not protrude from in front of the grip. Instead the magazine is reloaded just like the 9mm pistol.