Turrets damage formulas (and skill interactions) (PC version)

Base Damage (scaled to level vs enemy of the same level) = 14.48 * 1.13 ^ LvL for NVHM and TVHM with an extra * 1.1 in UVHM
From now on , I’ll call this parameter: BaseDamage
We also need to consider the ModifiedBaseDamage the first turret deployed uses for damage calculations
ModifiedBaseDamage = BaseDamage * (1/(1 + sum(penalties to turret damage))) .
The second turret deployed (gemini doesn’t get damage penalties from Axton’s ‘Scorched Earth’ or ‘Double Up’ skills) and uses straight BaseDamage for its calculations.

Turret starts with Gun Attack ability:

  • Fires (8 + 1 * # Sentry skill Ranks) bullets Bursts of NON-ELEMENTAL damage type
  • ~0.21 seconds delay between shots and reloads for 1.2 seconds between the bursts.
  • DAMAGE PER BULLET HIT (vs same lvl enemy, before elemental matching .) = ModifiedBaseDamage
  • So at 0/5 sentry fires 8 , reloads, fires 8, reloads 1.2s …
  • At 11/5 sentry fires 19, reloads, fires 19 , reloads 1.2s …

Scorched earth :

  • adds rocket barrage ability ( FIRES ROCKET BURSTS INDEPENDENTLY FROM THE GUN BULLETS so It would be pure damage gain BUT … see bellow )
  • adds 0.15 Damage penalty to ModifiedBaseDamage (affects only the first turret deployed, the second, gemini turret not affected)
  • Fires 22 rockets per burst. Each rocket does Explosive Damage and Splash Explosive Damage
  • IMPACT DAMAGE (per rocket) is ModifiedBaseDamage on the first turret (and BaseDamage on the second turret)
  • SPLASH DAMAGE (AOE per rocket) is ModifiedBaseDamage * 1.2 on the first turret (and BaseDamage * 1.2 on the second turret)
  • Burst duration is ~3.735s rocket pods reload speed is ~5.7s …
  • less accurate than the gun (gun NEVER misses vs immobile target, rockets sometimes miss but might track better vs moving targets )
  • Rocket pods are a huge damage spike in the turret’s output (relatively short duration burst for 48.4 times ModifiedBaseDamage). Even more so with ‘double up’ when they can still get *3 explosive vs slagged and the bullets turned into slag damage type can only get *1.5 vs slagged.

Double up:

  • adds 0.15 Damage penalty to ModifiedBaseDamage (affects only the first turret deployed, the second, gemini turret not affected)
  • turns gun damage type from NON-ELEMENTAL to SLAG. Chance to slag 30% per bullet vs enemy of same level.
  • ‘doubles’ the ROF of the gun. Same burst duration (dictated by sentry) (double the number of bullets fired per burst ) and same reload time.
  • nicer vs armor , less potential damage vs slagged non armor [ * 2 * 1.5 * penalty…]. Only the second (gemini) turret gets true double gun damage from this.


  • you get a second turret that uses BaseDamage for its damage calculations (not affected by penalties from ‘Scorched Earth’ or ‘Double Up’ )
  • keep in mind the penalties do get ‘amplified’ vs slagged targets

Closing observation maximum theoretical turret DPS output is WITHOUT Double Up with the player providing the slagging. (especially if deploying only one turret).
With gemini turret also on the field, the extra benefit from slagging most probably is worth the slight loss of maximum turret DPS output, and in practice might even provide superior DPS due to all the slagging and reducing the number of times Axton has to switch to a slagging weapon …

So while leveling up, without uber legendaries on axton … a build like this https://bl2skills.com/commando.html#54020110005500012000055050045101 (gemini + longbow) + engineer COM will give you better returns than something double up based.