This Machine

 is a weapon in Fallout: New Vegas.

Characteristics
 appears to be a pre-war M1 Garand, in excellent condition when first acquired. It is chambered in .308 and holds eight rounds at a time, and is essentially a unique Hunting Rifle of sorts.

Locations
is given to you by Contreras for not turning him in at the end of Free Quest: Dealing with Contreras, Camp McCarran. However, It seems it can also be acquired by hacking his computer and turning him in as well, as they "confiscate" from him. On the 360, one can also obtain the weapon in the following way: on the mission to meet Price, talk to Keller, and use the passphrase. When he replies, choose the option to say that is not the correct password. Attack him afterwards (dialog option), and then return to Contreras. The dialog will be bugged and you can choose the option that say you've convinced the ranger to work with him (in death), and he'll give you the gun.

Some people are experiencing a bug where they cannot receive the weapon if they used a diplomatic solution to the final part of Contreras's freequest.

Appearances
appears in Fallout: New Vegas.