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Borderlands 4 Build

Ordnance Outlaw Amon | Melt any UVH5 boss with infinite heavy ammo and huge damage over time!

Amon

Crucible

End Game

Creator

By caseybop

Updated on Sep 23, 2025

Sep 23, 2025

Build Overview

Welcome to my first real build guide for Borderlands 4, and hopefully the first of many. This build has the highest consistent damage output of any Amon build I've tried so far, and it does it through a very simple gameplay loop, with a bunch of more complex synergies under the hood. The basic premise of the build is to use Endless Bombardment and Primal Surge to achieve infinite ammo for most heavy ordnances in the game, and using said heavy ordnances to apply as many powerful status effects as we can through the Tail of the Comet and Blackout skills in Amon's blue tree. In addition, this build utilizes a pretty unique purple rarity class mod called the Outlaw to push its heavy ordnance crit chance, damage, and ordnance cooldown through the roof. I'm going to go as in-depth with this guide as I reasonably can, because this game is still brand new and many things are still unknown, and I would like for anyone reading this to truly understand the interactions and synergies going on under the hood of this build. If you enjoy this guide, please stop by my Discord server, and give my Twitch account a follow for when I eventually get my game performance optimized enough to actually be able to stream the game:

https://discord.gg/HfhhubpbaD

https://www.twitch.tv/caseybop

Without further ado, here's the best heavy ordnance build I've used in the game so far.

Strengths And Weaknesses

Great mobbing clear speed.
Great bossing damage.
Very simple to play.
Very future proof (very unlikely to be nerfed, and will most likely receive a huge buff after the Blackout bug is fixed. See the Notes section to read about the bug with Blackout).

Fight for your life damage is not good.
Have to keep an eye on your heavy ammo count as to not run out.
The specific class mod for this build is fairly difficult to come by. I got really lucky with the one that dropped for me.

Skill Tree

Points Spent 0 / 49

LMB Allocate

RMB Unallocate

5/5

4/5

1/5

1/1

4/5

1/5

4/5

2/5

1/5

Action Skill: Crucible

Using Crucible allows you to have constant uptime on all your forgedrones. This is very important as you will be using your forgedrones to activate your Kill Skills through the skill My Touch Is Death, all of which will provide drastic increases to your damage and ordnance uptime.

Augment: Axe and Stone

Axe and Stone will allow you to use your cryo axes, forgeskill, and even your basic melee attack in order to refund ordnance cooldown and increase your movement speed drastically for a short time. This is a very useful utility augment for this build.

Capstone: None

This build does not spec far enough into a Cybernetics branch to unlock a capstone, but that isn't an issue in the slightest. Most of Amon's capstone abilities modify his forgeskills to increase their damage, but this build rarely ever uses action skills or forgeskills, let alone for damage.

Cybernetics Skills:

Tier 1: Gathering Storm (5/5)

This is the first of the kill skills that will be activated by your forgedrones via My Touch Is Death. At 3 stacks, you'll be getting a consistent +30% elemental damage, which will feed into your ordnance damage and your damage over time.

Tier 1: Executioner (4/5)

Only take 4 points into this skill to move down the tree. +12% crit damage is never a bad thing, and this bonus will always be doubled because of your forgedrones.

Tier 2: Tempered Pyre (1/5)

This is the first of four forgedrone skills you will use in this build. Because this build doesn't care about the melee damage the drones are actually dealing, you only need to spend one point in this skill.

Tier 3: Twin Tempers (1/1)

This skill basically doubles up on the forgedrone skill above it. These two drones will both activate when you use your forgeskill, and they share a duration.

Tier 3: Vital Organs (4/5 + extra points from class mod)

This skill is the largest source of crit chance that this build gets, and it is the main reason that you want to use the Outlaw purple class mod with points into My Touch Is Death. My class mod grants me 3 points into this skill, so at 7/5 points, I'm getting a massive 42% increased gun critical hit chance that is always active during combat.

Cybernetics Left Branch:

Tier 4: Tempered Ice (1/5)

Another forgedrone skill, this time activated upon ordnance use, so this will always be active if you cycle in and out of your ordnance every once in a while.

Tier 4: Cacophany (4/5)

Only four points to move down the tree. +20% ordnance damage is a decent bonus.

Tier 5: Endless Bombardment (2/5)

This is one of two skills that will allow you to sustain infinite ammo on your heavy ordnances. Any heavy ordnance that consumes 1 ammo but causes several instances of damage will get a lot of value out of this skill. Only spend 2 points here in order to have enough points for the skills you want to get in the Vengeance tree.

Cybernetics Middle Branch:

Tier 4: Tempered Lightning (1/5)

The fourth and final forgedrone skill, this time activated when you use your action skill. Having all four drones active at once in combination with 3 points in My Touch Is Death from the class mod will allow for 100% kill skill uptime and tons of Machinist activations, without even having to kill anything. This is extremely important for any boss fights that have limited mobs.

Vengeance Skills:

Tier 1: Scorched Kairos (4/5)

Another +20% ordnance damage, plus 24% magazine size for some leeway while spamming your ordnance in case you miss your shots and waste ammo. Only 4 points to move down the tree.

Tier 1: The Thrill (3/3)

This is a very strong health regeneration skill that has saved me countless times during difficult encounters where enemies chew through my shield and leave me on death's door. Great skill for preventing going down, which can ruin your ordnance cooldown, and obviously, cause you to die. Always take this skill if you have the points for it, there's never really a reason to skip it if you're traveling down the Vengeance tree.

Tier 2: Tail of the Comet (5/5)

This is the first of two huge damage skills that this build utilizes. All ordnance damage has a 30% chance to activate a stacking cryo status effect that deals damage based on the hit that activated it. In other words, all the increases to your damage that you've received so far will all feed into this very powerful skill. The application chance also scales with increases to status effect chance. For example, if you have +100% status effect chance, then the 30% base application chance will turn into 60%. This is the reason you really want to use the Contamination specialization on this build, as it allows you to stack up this damage over time effect much faster, which is a huge increase to the build's DPS.

Tier 3: Machinist (3/3)

With your forgedrone skills proccing My Touch Is Death, this skill is activating all the time, even when you don't need it. It's a fantastic way to reduce the downtime between ordnance activations in case it goes on cooldown (spoiler alert: it will. This skill interaction is necessary to play this build smoothly in all content, without any big hiccups).

Vengeance Middle Branch:

Tier 4: Icy Rage (5/5)

This is the only skill in this build that actually increases out gun damage. It's not a huge amount, but it definitely helps, especially when it feeds into your heavy ordnance damage at a 150% effectiveness due to the Full Spectrum Arsenal specialization.

Tier 5: Primal Surge (5/5)

This is the second skill that allows this build to shoot heavy ordnances infinitely. Since you will be activating status effects constantly with the combination of Contamination, Tail of the Comet, Blackout, and Vital Organs, this skill will proc many times per second, refilling your heavy ordnance ammo and shield almost instantly. The shield restoration this skill gives is a perfect way to keep your Super Soldier active at almost all times.

Vengeance Right Branch:

Tier 4: Blackout (1/5)

This is the second powerful damage over time skill this build utilizes. You might notice that I have only invested 1 point into this skill. This is due to a very unfortunate bug that causes the damage over time on this skill to not scale with the points invested into it. For example, at 1 skill point invested, you'll get +3% ordnance crit chance and a shock status effect that activates on ordnance crit, dealing 21% of the initial damage per second. Both the crit chance and the damage over time effect are supposed to increase in value when you spend points in the skill, but unfortunately, only the crit chance is being increased with subsequent points. However, even with just the 1 point in the skill, it's a huge improvement to the build's DPS. If/when the skill is fixed, this build will want to invest in the skill as much as possible, as it should be a huge buff to the build as a whole. With all that being said, the build still performs extremely well at maximum difficulty with all content currently available.

Calamity Skills:

Calamity Left Branch:

Tier 6: My Touch Is Death (0/3 + points from class mod)

This skill is what makes most of this build possible, and it's the reason I went out of the way to use a non-legendary class mod. It enables so much of the build's damage and ordnance cooldown consistency that opting for a different class mod would chance the whole build's spec pretty drastically. You probably want at least 2 points into this skill from your class mod, with +3 being the optimal roll for the most consistency possible. If you want a good place to farm for purple class mods, you can farm Ripper Drill Sites as they tend to give a good amount of world drop loot. This farm will be even more effective if you do it with a co-op partner or two, and all farm one drill site each, which can potentially double or triple the efficiency.

Equipment

Weapons

Repkit & Ordnance

Utilities

Class mod: Purple Outlaw class mod with points in My Touch Is Death as first priority, and points in Vital Organs as second priority. Passives to look out for would be ordnance crit chance, gun crit chance, ordnance damage, gun damage, ordnance critical hit damage, gun critical hit damage, status effect application chance, status effect damage, and splash damage. Having points in My Touch Is Death is incredibly valuable for this build, as the forgedrones will be automatically activating all of our kill skills. The fact that this class mod can get points into Vital Organs as well is very important, as ordnance focused builds don't get the option to abuse the all-powerful Penetrator Augment Throwing Knives that are so popular in the early meta of this game. You need to get your crit chance naturally, so the value you get from constant uptime on Vital Organs should be self-explanatory. There are a few other good kill skills you're getting in this build as well, such as Gathering Storm for a good chunk of elemental damage, Icy Rage for some much-needed gun damage, and Machinist so you can refresh your ordnance cooldown very quickly in situations where you don't have access to your main source of damage (for example, going into Fight For Your Life while using your ordnance, and discovering that it went on cooldown after scoring a Second Wind).

Shield: Super Soldier. Shield augments don't matter too much, but damage or shield booster parts are ideal. This shield comes with many advantages: the +1/second flat ammo regeneration is great for holding infinite ammo with lower mag size/fire rate ordnances, the fire rate and movement speed are great DPS and quality of life additions, and the overshield generation when the energy shield fills gives you some good survivability. You'll be able to keep this shield topped off basically all the time using the shield regen from Primal Surge.

Enhancement: This part depends on what weapon you want to use for Fight For Your Life and any potential downtime between ordnance uses. I like to use the Chuck, so I use a Digi-Divider tediore enhancement to boost its power.

Repkit: There's a few options you can use here. I have been using an Order Repkit with the Speed and Go Go Gadget augments for some speed for utility, as well as to shorten any potential downtime between ordnance uses. I like to use Order repkits for the extra charge. You can also use a Triple Bypass, or an AF1000 with whatever augment you feel is best for you.

Ordnance:

This is where a lot of variation occurs. Considering this is a heavy ordnance build, there are naturally a LOT of different options that perform incredibly well. I'll just go ahead and list what I think are overall the best options for certain types of content, as well as some that I just think are fun to use with this setup:

Dense mobbing areas:

- Bottled Lightning - This gun shoots orbs that connect to all surrounding enemies with these little shock tendrils. Each tendril deals damage very quickly, making it a great weapon for applying stacks of Tail of the Comet and Blackout to every enemy in your area code, as well as making it very easy to hold the trigger down and sustain infinite ammo with Endless Bombardment and Primal Surge. Try to get one of these with a mag size of 3, so you run less risk of accidentally shooting too much before your ammo return skills can kick in. This gun is also great for bosses with large shield bars, so don't be afraid to bust this out for bossing as well.

- Disc Jockey - While not covering wide areas as consistently as the Bottled Lightning, it's going to start dealing that damage sooner without the bit of ramp-up that the Bottled Lighting usually has to deal with. Just be careful to hit your shots with this weapon, because while the ricochets will eventually get around to hitting enemies, you might run out of ammo before that happens. This is best used in shorter bursts to clear smaller sections of the map very quickly, or to lay into those tanky badass enemies while everything around it succumbs to the ricochets.

Bossing:

- Streamer - This gun performs incredibly well when fired at large and/or stationary enemies, such as bosses. The amount of damage instances that are being dealt when holding down the fire button allows for an incredible amount of Tail of the Comet and Blackout stacking, melting these beefy enemies in a matter of moments. I would not use this gun for mobbing over others listed above, but if it's all you've got, you can make it work. The stationary projectiles make for a bit of a learning curve when firing, but it's not too hard to get the hang of it, especially when you have Endless Bombardment and Primal Surge providing you with infinite ammo. If you can line up all the beams into a crit spot, it might just be the highest DPS weapon for this build.

- Maliwan Heavy Weapon - The specific gun you want to look for here is called the Rainband. On its own, this generic purple gun isn't anything too special, but it really shines when it drops with the right parts. You really want a MIRV part on these things, as that is great way for them to not only proc more status effects with Tail of the Comet and Blackout, but also help keep up with the ammo cost using Endless Bombardment and Primal Surge. The two other parts to look for would be Proxy Homing, making both the initial projectile and the MIRV projectiles hit your enemies more consistently, and Two-Shot, which I feel I don't need to explain why that is a good part to find along with MIRV. With the right part combos and element matchups, this gun can melt bosses in the blink of an eye, and with a homing part, they can be a great mobbing tool as well. Just pay attention to the range you shoot this at, as it's likely to down you very quickly if it hits you.

Honorable mentions and fun stuff:

- Vladof Heavy Weapon - If you can find a Vladof Ootka heavy weapon with Explosive Rounds and Two-Shot parts, it can prove to be a deadly weapon while mobbing and can even put in work against some of the easier bosses in the game. If you find one, make sure to pick it up and try it out.
- Atling Gun - Homing minigun go brrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr (decent for stacking status effects, easy to maintain infinite ammo. Not the best DPS, but still worth trying out if you like to shoot incredibly quickly for extended periods of time).
- Ravenfire - This is the typical launcher type weapon. Very fun to use even if it's not exactly optimal for this build.

If you discover any more noteworthy heavy weapons to use with this build, you can let me know by joining the Discord server in my profile.

Firmware

Repkit & Ordnance

Repkit FirmwareDeadeye

Ordnance FirmwareGadget Ahoy

Utilities

Class Mod FirmwareDeadeye

Shield FirmwareDeadeye

Enhancement FirmwareGadget Ahoy

Get 3 levels of Deadeye for the crit damage, other 2 slots are personal preference but I like to use 2 levels of Gadget Ahoy.

Specialization

Specialization 1Contamination

Specialization 2Fragmentation Payload

Specialization 3Compounding Afflictions

Specialization 4Full Spectrum Arsenal

Contamination / Compounding Afflictions

These perks are a must-have for any build that heavily utilizes Tail of the Comet and Blackout. Contamination lets us proc a lot more instances of Tail of the Comet, and when you combine all of those stacks with the stacks of Blackout you get from all the crit chance bonuses we have, you can get crazy amounts of increased damage from Compounding Afflictions.

Full Spectrum Arsenal

Full spectrum arsenal allows you to get a lot more value out of any gun damage increases you might have. It's a great choice for any heavy ordnance build.

Fragmentation Payload

This perk is a must-have for every ordnance-focused build in this game. The crit chance is of course nice, but the 50% crit damage is the real value in this perk. The more we crit, the more we stack Blackout, and the more damage our crits do, the more damage the subsequent Blackout and Tail of the Comet procs will do.

Gameplay

The gameplay loop for this build is extremely simple. All you need to do is activate your action skill and your forgeskill when entering combat (you don't even need to hit anything unless you need to use Axe and Stone for ordnance cooldown) in order to spawn all your forgedrones, then activate whatever heavy ordnance you've decided to use, and just shoot away while making sure to keep your ammo topped off. You may occasionally want to reactivate your forgedrones, so to do that, just put away your ordnance after making sure it's got full ammo, reactivate your action skill and forgeskill to either refresh or reactivate the drones, then you can go back to being trigger happy. If you need to get your ordnance cooldown back in the heat of battle, you can pop a repkit charge, throw a cryo axe at an enemy or two, and detonate them by either throwing your forgeskill or just punching them. Doing that while your drones are automatically activating Machinist for you should result in some incredibly quick ordnance cooldown recoveries.

Notes

Unfortunately, at the time of creating this guide, one of our main damage skills, Blackout, is bugged in a very critical way. Investing more than 1 point into the skill does not yield increases to the shock status effect that is applied by ordnance crits. However, the ordnance crit chance is working as intended. This skill is still a very powerful addition to the build even with one point, so you can imagine the damage output with this build once this bug is fixed. If/when it is fixed, I will make an updated/overhauled version of this build, so keep an eye out for that.