BNK-3R has a cluster of optics at the front and a large swivel eye underneath that offer several readily accessible critical hit spots when it stops to attack. The turrets are similarly vulnerable targets and can be shot for Second Winds.
After Where Angels Fear to Tread is completed, BNK-3R will respawn on every entry to the map, including re-entries within the same game session.
BNK-3R has a 10% chance to drop only one of the following rare items:
When BNK-3R is destroyed, it will disperse loot across much of The Bunker. Care should be taken when searching for loot, as items can fall into gaps in the floor and become inaccessible. In addition to the loot strewn across the Bunker, it will continue to "drip" loot from its main cannon several times.
BNK-3R may sometimes get stuck upon the top level of the complex, preventing it from being destroyed. Jumping onto it from a higher point may sometimes free the BNK-3R, otherwise a restart is required.
If Zer0's B0re is triggered, it is possible to hit multiple hitboxes on the sides of the BNK-3R and deal large amounts of damage from a single bullet. However, the exploit sometimes causes BNK-3R to glitch and rendered unable to be interacted with. The B0re exploit is successful if a loud noise caused by the stacking of B0re is heard.
Glitched death
Triggering the exploit in multiplayer while multiple players are attacking the BNK-3R can result in the BNK-3R crashing where it is without first relocating to the front of the Bunker. Consequently, it can land on one of the circular side walkways, making the loot obtainable, but it can also explode in mid-air, making the loot impossible to get.
It is also possible in single-player to cause any and all issues with BNK-3R's crash locations. This includes BNK3R crashing sideways into the archway, being destroyed and starting its 'crash' animation sequence in mid-air, and being destroyed in mid-air leaving the body to 'float' away. The easiest way to cause this is to use the Commando's Sabre Turret at a high level. If done properly, BNK-3R's health will drop to near zero before stopping so that it would be able to fly back to the archway. Finishing BNK-3R off with any type of damage while it is circling around causes it to start its death sequence in an odd orientation and location.
Rarely, BNK-3R can collide with the circling friendly buzzards which may cause a delay in its flying sequence. Destroying BNK3R before it has flown free of the obstruction can cause it to drop loot away from the platforms.
Killing BNK3R doesn't grant second wind even if it is at the top of the archway.
The parts of BNK3R that spawn turrets are considered Constructors and will count towards the Challenge Constructor Destructor.
Trivia
The number on BNK-3R's intro graphic, 00101010, translated from binary to decimal, is 42. The number 42 is reputed to be "The Answer to the Ultimate Question of Life, the Universe, and Everything" in The Hitchhiker's Guide to the Galaxy.
According to "Inside the Vault: The Art & Design of Borderlands 2", sound designer Joshua Davidson provided BNK-3R's voice. "When you hear BNK-3R taunting you, it's really just me yelling about tea through heavy audio processing."
