"Thunderhead" Heavy Autocannon

DRG

DRG:RC

DRG:S

OverviewDwarvesGunnerEquipmentAutocannon

This page is up to date for Season 05: Drilling Deeper

Updated for S5

Unlocked through an assignment.
Requires Gunner 10 Purchased for: 7 600 Credits 80 Croppa 120 Magnite

“	A peculiar but devastating weapon. The slow rate of fire is made up for by heavy damage, delivered with glee by the belt-fed .50-caliber tungsten rounds. The Thunderhead is a somber weapon for the sophisticated executioner, delivering death as inexorably as the passage of time itself.
	— Item Description

The "Thunderhead" Heavy Autocannon is an unlockable primary weapon for the Gunner. It is an oversized heavy machine gun with two massive barrels extending outwards which fire in sequence. The weapon is loaded by a huge double ammo drum.

The Autocannon fires explosive rounds which detonate upon hitting the world or a target. Enemies hit directly by rounds take both the damage of the bullet and the explosive damage at once. The rounds fired start out with a sluggish fire rate, but this can build up over time the longer the trigger is held.

Pressing the reload key while the weapon is full will cause the Gunner to pull a bullet out of his pocket and balance the tip on his hand for a moment before returning the bullet to his pocket.

Modifications

There are five tiers of modifications and each tier has two to three upgrades. Only one modification can be equipped per tier.

"Thunderhead" Heavy Autocannon Modifications
	Mod	Effect	In Game Description	Price
Tier 1	Increased Caliber Rounds	+3 Damage	"The good folk in R&D have been busy. The overall damage of your weapon is increased."	1 200 Credits 25 Bismor
	High Capacity Magazine	x2 Magazine Size	"The good thing about clips, magazines, ammo drums, fuel tanks ...you can always get bigger variants."	1 200 Credits 25 Enor Pearl
	Expanded Ammo Bags	+220 Max Ammo	"You had to give up some sandwich-storage, but your total ammo capacity is increased!"	1 200 Credits 25 Croppa
Tier 2 4	Tighter Barrel Alignment	x0.7 Base Spread	"Improved accuracy"	2 000 Credits 24 Croppa 15 Enor Pearl
	Improved Gas System	+2 Top Rate of Fire +0.3 Starting Rate of Fire	"We overclocked your gun. It fires faster. Don't ask. Just enjoy. Also probably don't tell Management, please."	2 000 Credits 24 Jadiz 15 Enor Pearl
	Lighter Barrel Assembly	+50% Rate of Fire Growth Speed +0.6 Starting Rate of Fire	"Reach the max rate of fire faster"	2 000 Credits 24 Enor Pearl 15 Bismor
Tier 3 8	Supercharged Feed Mechanism	+2 Top Rate of Fire +0.3 Starting Rate of Fire	"We overclocked your gun. It fires faster. Don't ask. Just enjoy. Also probably don't tell Management, please."	2 800 Credits 50 Croppa 35 Jadiz
	Loaded Rounds	+2 Area Damage	"Increased splash damage"	2 000 Credits 35 Magnite 50 Umanite
	High Velocity Rounds	+4 Damage	"The good folk in R&D have been busy. The overall damage of your weapon is increased."	2 800 Credits 50 Magnite 35 Enor Pearl
Tier 4 12	Hardened Rounds	+400% Armor Break Bonus	"We're proud of this one. Armor shredding. Tear through that high-impact plating of those big buggers like butter. What could be finer?"	4 800 Credits 72 Jadiz 48 Magnite 50 Enor Pearl
	Shrapnel Rounds	+0.6m Effect Radius	"Greater splash damage radius"	4 800 Credits 72 Jadiz 50 Magnite 48 Umanite
Tier 5 16	Feedback Loop	+10% Damage at Top Rate of Fire	"Increased damage when at max rate of fire"	5 600 Credits 140 Croppa 64 Magnite 70 Bismor
	Suppressive Fire	+Impact Fear AoE (50% Fear within 1m of a bullet impact)	"Chance to scare creatures next to a bullet impact"	5 600 Credits 64 Magnite 140 Umanite 70 Bismor
	Damage Resistance At Full RoF	+50% Damage Resistance at Full Rate of Fire	"Take significantly less damage when at max rate of fire."	5 600 Credits 64 Croppa 140 Jadiz 70 Enor Pearl

Overclocks

Overclock calculations happen after modifiers.

"Thunderhead" Heavy Autocannon [Expand/Collapse]
Overclock	Effect	In Game Description	Price
Composite Drums	+110 Max Ammo -0.5s Reload Time	"Lighter weight materials means you can carry even more ammo!"	7 850 Credits 135 Croppa 105 Magnite 70 Enor Pearl
Splintering Shells	+1 Area Damage +0.3m Effect Radius	"Specially designed shells splinter into smaller pieces increasing the splash damage range."	7 300 Credits 95 Croppa 125 Jadiz 65 Magnite
Carpet Bomber	x1.35 Area Damage x1.45 Effect Radius -7 Damage	"A few tweaks here and there and the autocannon can now shoot HE rounds! Direct damage is lower but the increased splash damage and range lets you saturate an area like no other weapon can."	7 350 Credits 120 Croppa 105 Magnite 70 Umanite
Combat Mobility	+35% Movement Speed While Using x0.7 Base Spread x1.5 Rate of Fire scaling +0.9 Starting Rate of Fire x0.5 Magazine Size	"Fancy custom ammo drums improve weapon balance making it more accurate and easier to handle on the move while the improved feed motor increases the speed with which the max fire rate is reached. All this however comes at the cost of magazine capacity."	7 650 Credits 70 Croppa 120 Jadiz 95 Magnite
Big Bertha	+12 Damage x0.7 Base Spread x0.5 Magazine Size -110 Max Ammo -1.5 Top Rate of Fire	"Extensive tweaks give a huge bump in raw damage at the cost of ammo capacity and fire rate."	8 400 Credits 105 Croppa 80 Umanite 125 Bismor
Neurotoxin Payload	+Neurotoxin Payload (50% Chance) x1.25 Effect Radius -6 Area Damage -110 Max Ammo	"Channel your inner war criminal by mixing some neurotoxin into the explosive compound. The rounds deal less direct damage and splash damage, but affected bugs move slower and take lots of damage over time."	8 100 Credits 100 Croppa 75 Jadiz 135 Magnite
Mortar Rounds	Weapon fires mortar projectiles x7 Area Damage x1.25 Effect Radius -14 Damage x0.318 Magazine Size x0.318 Max Ammo x0.5 Top Rate of Fire	"The weapon has been reworked to fire heavy mortar projectiles. These modifications slow down the rate of fire significantly -- but even if you can't carry as many, the high-explosive rounds more than make up for it in damage. Just remember to account for drop."	7 300 Credits 140 Croppa 70 Jadiz 110 Magnite

Stats Breakdown

Understanding the Weapon

• Damage is how much damage is dealt upon direct impact of the shot.
• Area Damage is how much damage is dealt in addition to the direct damage within the damage radius around the impact.
• Top Rate of Fire is the max rate of how quickly shots can be fired after sustained firing.

Rate of Fire Mechanics

• The Autocannon has two hidden stats regarding rate of fire, which is its Starting Rate of Fire and Rate of Fire Scaling. They play an important role in determining how quickly max rate of fire bonuses are applied, and can be changed depending on which modifications/overclocks are taken.
• Starting Rate of Fire default is 3.4
  • This determines how quickly shots are initially fired as its rate of fire starts to ramp up.
• Rate of Fire Scaling default is 0.4
  • This is the coefficient of the exponential function that is used during the rate of fire rampup. The Autocannon's initial rate of fire continues to be scaled until the top rate of fire has been reached, which would then allow max rate of fire bonuses to be applied.

• Rate of Fire Formula
  • Let S be the Starting Rate of Fire
  • Let C be the Rate of Fire Scaling
  • Let M be the Max Rate of Fire
  • Let t represent the amount of seconds that has elapsed since the Fire button has been held down.
  • The Rate of Fire at any given time, t, can be represented as such:
    • $R(t)=\min (S*e^{Ct},M)$
  • Such that when enough time has elapsed and $S*e^{Ct}\ge M$, time is no longer a factor in the Rate of Fire. At this point, the "Max Rate of Fire" Bonuses should kick in.

Rate of Fire Graph

Modifications	Starting Rate of Fire	Rate of Fire Scaling	Max Rate of Fire	Time to reach Max Rate of Fire
Base	3.4	0.4	5.5	1.2s
IGS or SFM	3.7	0.4	7.5	1.76s
LBA	4	0.6	5.5	0.53s
IGS + SFM	4	0.4	9.5	2.16s
LBA + SFM	4.3	0.6	7.5	0.92s

Rate of Fire Graph (with Big Bertha)

Modifications	Starting Rate of Fire	Rate of Fire Scaling	Max Rate of Fire	Time to reach Max Rate of Fire
Base	3.4	0.4	4	0.4s
IGS or SFM	3.7	0.4	6	1.2s
LBA	4	0.6	4	0s
IGS + SFM	4	0.4	8	1.73s
LBA + SFM	4.3	0.6	6	0.55s

Rate of Fire Graph (with Combat Mobility)

Modifications	Starting Rate of Fire	Rate of Fire Scaling	Max Rate of Fire	Time to reach Max Rate of Fire
Base	4.3	0.6	5.5	0.41s
IGS or SFM	4.6	0.6	7.5	0.81s
LBA	4.9	0.9	5.5	0.12s
IGS + SFM	4.9	0.6	9.5	1.10s
LBA + SFM	5.2	0.9	7.5	0.4s

Rate of Fire Graph (with Mortar Rounds)

Modifications	Starting Rate of Fire	Rate of Fire Scaling	Max Rate of Fire	Time to reach Max Rate of Fire
Base	1.36	0.4	2.75	1.76s
IGS or SFM	1.48	0.4	3.75	2.32s
LBA	1.6	0.6	2.75	0.9s
IGS + SFM	1.6	0.4	4.75	2.72s
LBA + SFM	1.72	0.6	3.75	1.29s

Unique Overclocks

Unique Overclocks
Neurotoxin Payload	Neurotoxin Payload is an Unstable Overclock. It grants all shots a 50% chance to inflict Neurotoxin onto an enemy. When an enemy is affected by Neurotoxin, they will take 12 Poison damage every 0.75 - 1.25 seconds for 10 seconds, as well as having their movement speed reduced by x0.7. Hitting an enemy who is already affected by Neurotoxin with another round which inflicts the debuff will reset its timer.
Mortar Rounds	Mortar Rounds is an Unstable Overclock. It replaces hitscan shots with slow-moving projectiles that fly in an arch and can deal both self-damage and friendly fire.

Mastery

Each modification that is purchased advances a mastery bar by one unit.

Mastery unlocks:

• Three modifications – First Stripe Weapon Paintjob
• Seven modifications – Deepcore Weapon Paintjob
• All (14) modifications – The Company Special Weapon Paintjob

Skins

Full gallery of skins can be seen at Weapon Skins.

Gallery

Trivia

• Mission Control's dialogue upon completing the Weapon License Assignment for the Autocannon reads as follows:
  • "Good work. Management believes you're ready to handle our Heavy Autocannon, the "Thunderhead"... Be mindful not to blow off your own legs with it. This thing has a proper kick to it."
• In older versions of the game the Powered Minigun also fed from a large ammo drum which needed to be reloaded, on top of its overheating issues. This was changed in Update 11: Dead and Gun to the current system where the Minigun feeds from a single drum and does not reload. It is likely that the Minigun's older reloading system influenced the Autocannon's design when it was added to the game a few months later in Update 19: Guns! Lots of Guns!

• Before Season 01: Rival Incursion, the Autocannon was incapable of dealing friendly fire to teammates.
• The minimum caliber for an autocannon is normally considered to be 20mm. The Thunderhead's description states it shoots .50 cal, and as such the Thunderhead is either a heavy machinegun or shoots actual 20mm rounds (which would normally induce a devastating recoil). It is possible the thunderhead fires 20 mm or above and uses sub calibre rounds like apcr.