“This Machine” is a unique Battle Rifle that can be acquired by completing the unmarked quest “Dealing With Contreras”, which has 2 different ways in which you can finish it. In this guide, I’ll show you the faster and easier of the two ways. 

Quick tips before you start the quest:

• NCR settlement. To get this gun, you’ll have to interact with a lot of high-ranking NCR soldiers within Camp McCarran. This means that the gun is virtually impossible to get if you are hostile to the NCR.
• Science of 50 or higher required. To finish this quest, you’ll have to have a Science skill of 50 or above. 

Acquisition

To start the quest, start by going to Camp McCarran, located south of the Strip. 

To enter Camp McCarran, locate and go through the metal garage door. 

Follow the road leading to the right of the entrance. 

You’ll eventually see multiple sets of doors, which act as the entrances to the lobby. Enter through any of the doors. 

Once you enter the lobby, go up either one of the escalators.

Once you climb the escalators, turn towards the back of the building, you should see a large sign that says “Concourse”, go there.

You’ll see several doors at the end of a wide corridor. Go through any one of them.

You’ll enter the concourse. Go forward until you reach the center.

Turn slightly to the left. You’ll see a set of 4 doors. Go there.

Go down the slope and follow the hallway.

You’ll see another set of doors, but here, all but one of them will be barricaded. Go through that door.

Immediately turn left and walk up the stairs you see there.

Turn right and you’ll see an Average-locked terminal. Hack it and read the note inside.

Once you read it, go back to the escalator.

Once there, turn to the left of the escalator. There will be two doors there. Take the one to the left. If you can’t see the two doors, ensure that you are on the western side of the building.

Inside, you’ll see Lieutenant Boyd, speak to her.

Select the following dialogue options:

• I have proof that Sgt. Contreras is involved in criminal activity.

• I hacked into his computer and found evidence that he’s selling NCR guns.

Selecting that dialogue option will finish the quest and Boyd will give you the rifle as a reward.

Comparing the Battle Rifle to This Machine

• This Machine deals slightly more damage (55 damage vs 48 damage).
• This Machine attacks slightly faster (2.14 attacks/second vs 1.93 attacks/second).
• This Machine is slightly more accurate (0.5 spread vs 0.55 spread).

Gameplay Tips

• The sights on this weapon are slightly offset to the right, meaning that you’ll have to adjust your sights accordingly to hit your shots.
• This weapon, unlike what the perk implies, is not affected by the Grunt perk.
• Despite being a unique version of the battle rifle, there is no non-unique version present in the base game. To get the non-unique variant, you’ll have to buy it off of a merchant after installing the Gun Runners Arsenal DLC.