XBOW

A crossbow is a weapon consisting of a bow mounted onto a stock that shoots projectiles named bolts or quarrels at parabolic arcs. Their first major usage originates in China around 600 B.C.. Although they see very little use in modern militaries, crossbows are still used for hunting and recreational target shooting. Modern crossbows can be mounted onto rifle receivers, allowing accessories such as optic sights to be easily added.

Battlefield 3
The XBOW is an improvised crossbow appearing in the Battlefield 3: Aftermath expansion pack.

According to a post in the Battlefield Blog, it is described as a jury-rigged weapon made from a malfunctioning M417 rifle, wire from a broken down car, scrap metal for the bow, and a optical sight like the Red Dot Sight or PKS-07 as shown in the trailer and preview screenshots.

It is unlocked by winning 3 rounds of Scavenger.

Bolt Types
Standard bolts are the starting ammunition type. These three non-standard bolts are unlocked via assignments. (default on PC,  on consoles) switches between the bolt types. Bolts can only be changed after the bow is fully loaded.

Standard Bolt
The Standard Bolt is the default bolt type for the XBOW. It inflicts fatal damage at close range, and can kill with a headshot at any range. Due to its barbed head, it has a higher bolt drop compared to the balanced bolt thus limiting its range, but giving it greater damage in close quarters.

HE Bolt
"High explosive bolt against vehicles with almost no splash damage and a short trajectory."

- Battlelog description

The High Explosive Bolt is tipped with C4 that explodes on impact. It does not deal as much damage as an actual C4 charge or an RPG shot, but it can still disable scout choppers (AH-6 and Z-11W) and light transports in a single shot, and take out small groups of infantry, although the explosive radius is the smallest of any explosive device in the game.

It drops much more than the other bolts, making it difficult to use at medium range. It can inflict self-damage at very close range, as with other explosives.

The HE Bolt is unlocked by completing the assignment A Good Demo Man, which requires the player to get:
 * 5 kills with hand grenades
 * 5 kills with underslung grenades
 * 5 kills with C4

Scan Bolt
"Scan bolt fires a sonic sound on impact spotting enemies within a 10 meter radius."

- Battlelog description

The Scan Bolt is tipped with a radio emitter that scans for enemies in a 10m radius. Scanned enemies are automatically spotted with a special flashing icon. The radio head inflicts minimal damage, least among the bolt types. Infantry that have been spotted by the bolt can hear a distinctive trill upon its impact.

The Scan Bolt is unlocked after completing the assignment It Is Ok To Thank Me, which requires the player to get:
 * 20 spot assists
 * 10 vehicle laser designations
 * 1 designated assist

BA Bolt
"Balanced bolt is a long range, medium damage bolt with almost no drop because of stabilizers on the arrow."

- Battlelog description

The Balanced Bolt, being more aerodynamic due to it being double-feathered, has the most range among the bolt types, but does slightly less damage with its thinly-tipped head, meaning that one-hit kills will only occur on headshots.

The BA Bolt is unlocked after completing the assignment Stay Away From My Tent, which requires the player to get:
 * 50 kills with sniper rifles.
 * 10 headshot kills with sidearms.

Sights
The XBOW with Kobra sight is easily obtained via the Sticks and Stones assignment. This assignment unlocks all the other XBOW-related assignments upon completion.

The PKS-07-equipped XBOW is awarded by the Go Play Close Quarters assignment.

Aside from differences in targeting and scope sway, the two weapons are functionally identical.

Ranging
* Lower accuracy hinders use of these bolts when hipfiring at long range.

&dagger; Drop rate and splash damage of HE bolt makes these markings useless at close range.

Trivia

 * The lower part of the XBOW, the M417 receiver, has its ejection port, bolt release button, and magazine well taped shut.
 * Separate Battlelog stats are kept for the XBOW and XBOW SCOPED.
 * In the Battlelog, once clicked on, the page for the XBOW SCOPED is equipped with the US 8x rifle scope instead of the PKS-07 scope it actually uses.
 * The XBOW is the only weapon in Battlefield 3 other than a Shotgun or Grenade Launcher that is capable of switching between different types of ammunition, and the only weapon aside from the mortar capable of doing so in the middle of gameplay.
 * The self-inflicted splash damage radius of the HE bolt is very small (about one meter). Players shooting at the ground beneath them can avoid taking damage near the apex of their jump, or from elevated ledges (train platforms, entrance staircases).
 * The scan bolt is mainly comprised of a T-UGS sensor without its tripod.