Deploying your Sabre Turret sets off a small nuclear blast.
Nuke is the tier 6 skill in Axton's Gunpowder skill tree. When Axton deploys his turret after investing in this skill, a large nuclear blast detonates at the spot where the turret appears.
Special Skill Text
"Impotent and Obsolete? Hardly."
The skill manifests as a large nuclear explosion emitted around the turret's location with a radius of about 15 meters. Explosive damage is applied to anything within range, even to targets hidden behind cover (such as barrels, fences and walls), and fire damage is applied to anything that survives the initial explosion. Both the explosive and the fire damage scales to the Commando's level, but is not further increased by skills, relics, or Badass Rank. The explosion does not harm Axton, the turret, or any allies (though as usual, one must take note of hazardous explosive barrels that may be ruptured by the nuke).
With the release of UVHM, it is possible to earn a rank in Gemini, Longbow Turret, and Nuke simultaneously. As a result, "nuke snipers" are now a viable build: Commandos with all three skills, particularly those who take specialization in turret cooldown, may now deploy a Nuke-turret at enemies from long range, immediately deploy one at very close range, and then immediately recollect the nearer turret (un-deploying both). Because Axton's turret rewards premature recollection with a shorter cooldown period, players with such a skill combination can frequently launch Nuke turrets from extreme range with equally extreme impact.