## FANDOM

25,675 Pages

April 2018: Tri-Beam, LAER, Elijah's LAER, Multiplas DPS updated.
March 2018: Calculations have been vastly improved and expanded upon.
Feb 2016: First release.

## Introduction

Figuring out the best weapon for a situation is very hard. It's probably more difficult than you realize. I will now attempt to figure out what the highest DPS weapon is in the game while taking into account as many variables as possible. If you want to just jump straight into the results, go ahead. But I think you will fail to appreciate just how far I've went to try to make my data as true as possible.

1. You don't care about sneak damage.
2. You are playing on PC and will use YUP to fix glitchy perks, but not other gameplay mods.
3. Gun condition is always 100%. (Anything but 100% CND means lower crit rate.)
4. Your character is maxed out. 10 SPECIAL, all the relevant perks, infinite supply of any ammunition, etc.
5. You are wearing the outfit that gives the highest critical chance.
7. You are not doing VATS, headshots, special attacks, or power attacks.
8. You use almost all drugs, except from poisons and Daturana Root.
9. Your primary concern is DPS.
10. You need to empty your clip and reload at least once before all the enemies are dead.
11. You will click attack exactly 5.5 times per second while aiming perfectly at the enemy.
12. Your attacks with explosive weapons are direct hits.
13. You are playing on Very Hard difficulty.
14. There are no enemy-specific perks that increase your DPS against the enemy you are facing.
15. You are not under the influence of the highly situational Atomic! perk.
16. The opponent does not have any DR.
17. You are primarily concerned about the DPS of weapons for the player, not the companions.

VATS increases 'base unarmed/melee damage' for non-thrown weapons by two. It also increases critical hit chance by 5-6%. Things like Camarader-E changes this. Perks like Center of Mass further muddies the water. The DPS values here assume the player does not have the perk or hits the enemy limbs instead. No, I can't calculate DPS factoring in accuracy. You have to decide what spread is good enough for a given purpose.

## Perks

No attack speed bonuses, be it from perks or consumables, work for automatic weapons. Nothing in the GECK states that this will happen, but that's what happens in practice. If you don't understand this you have no clue how DPS works in this game.

Perk Choices
The level 50 perk chosen is a major and irreversible decision (absent of console commands) that affects weapons a lot in different ways. There's +50% critical damage, +10% damage (and +100 max HP), and +20% firing rate. 20% firing rate is useless for automatics right off the bat. On top of this, there is a realistic speed cap for each weapon, and your weapon will wear out faster (decreasing combat effectiveness). It is very rarely the highest DPS perk to take so it's out. The luck bonus of Just Lucky I'm Alive is pointless given that you have 10 SPECIAL. On the other hand, most of the time it nets the highest DPS. Finally, Thought You Died still gives a good DPS boost and gives an extra 100 max HP, which is very useful. Crit damage tends to be better against heavily armored enemies, while damage perk tends to be the best in select circumstances against medium or lightly armored enemies.

Fast Shot: You will get more scope sway and a 20% penalty in accuracy, but in exchange you will get a 20% increase in attack speed for non-unarmed or melee weapons. In VATS the 20% decrease is mostly mitigated due to perks, but the same can't be said for free-fire. You also get 20% decrease in AP usage, but this article assumes VATS is not used. This is a more subjective decision. However, this trait is all downside for automatic weapons, so chose wisely. The chart you will soon see does not include the penalty of Fast Shot for automatic weapons, which they would have if you have Fast Shot and want to get the most out of your short-ranged or non-automatic weapons. It will assume that Fast Shot was used for all the non-automatic weapons, with its spread adjusted accordingly.

Heavy Handed: You get a 20% damage increase and a 60% decrease in critical damage. This perk always lowers DPS because critical damage is a huge part of melee and unarmed weapon DPS. It also doesn't affect guns, so this trait is objectively terrible.

Universal Perks & Chems
1.05 (Bloody Mess) * 1.04 (Lord Death) * 1.1 (Yao Gui Meat) * 1.25 (Slasher or Psycho) = 1.5015 or 50.15% damage boost.

Non-Universal Perks & Chems
Shotgun Surgeon - Enemy DT -10 for shotguns.
Cowboy - 25% damage boost to all revolvers, lever-action firearms, dynamite, knives, and hatchets.
Laser Commander - 15% damage boost to all laser weapons.
Grunt - 25% damage boost to many guns and a few knives. Note: Grunt does not affect DLC weapons outside of Honest Hearts without a bugfix mod.
Demolition Expert - 60% damage boost to explosive weapons.
Slayer - 30% speed increase for melee and unarmed attacks.
Melee Hacker - 10% speed increase for melee and unarmed attacks.
Pyromaniac - 50% damage boost to all fiery weapons.

Perks like Grunt do not affect weapons for other DLCs, but this is fixed in YUP. Rushing Water, Fast Shot, and Ain't Like That Now can all increase attack speed. Melee and unarmed weapons don't have Fast Shot but do have Slayer and Melee Hacker. Weapon Binding Ritual increases unarmed and melee by a flat 10. The Daturana Root increases unarmed damage by 1 but decreases agility by 2. The effect of the Daturana Root is too small to matter, and I have decided to ignore it.

## Critical Hit System

The DT of your opponent along with the chems, perks, critical chance/damage, and ammo type will affect which option nets the highest DPS. This article sidesteps almost all of those factors. Let's take a look at how the critical hit system works.

(Base Crit Chance * Weapon Crit Multiplier) + Flat Crit Modifiers = Actual Crit Chance

The 'base crit chance' can be found by typing "player.getav critchance". As you can see, "Flat Crit Modifiers" apply after the weapon multiplier and base crit chance are figured out.

A flat crit modifier is superior to a regular crit modifier. A good way to show this is with a high rate of fire weapon and a low base critical chance. Here's a quick comparison, assuming you have a minigun and a base critical rate of 10%. It has a weapon critical multiplier of 0.02.

(0.1 * 0.02) + 0.1 = 0.102
(0.2 * 0.02) + 0 = 0.004

Let's look at the highest critical chance build you can make in Fallout: New Vegas.
5% - 1st Recon Beret
5% - Ulysses Duster (NOT Elite Riot Armor, as you lose Light Touch.)
10% - 10 Luck
3% - Built to Destroy
5% - Finesse
10% - True Police Stories w/ Comprehension
---
38% Base Crit Chance

Flat Crit Modifiers:
5% - Light Touch
15% - Ninja (Unarmed/Melee) (Ninja is a base crit chance modifier due to a glitch. Patched on PC, it's a flat crit modifier.)
4% - Set Lasers for Fun (Energy Weapons)
10% - Laser Commander (Laser Weapons)
5% - VATS

Crit Chances w/o VATS:
Guns - (0.38 * Weapon Crit Chance) + 0.05
Energy Weapons - (0.38 * Weapon Crit Chance) + 0.19
Non-Laser Energy Weapons - (0.38 * Weapon Crit Chance) + 0.09
Melee & Unarmed - (0.38 * Weapon Crit Chance) + 0.20

Now let's look at critical damage. Fortunately, this part is pretty simple.

50% - Better Criticals
50% - Just Lucky I'm Alive
50% - Elijah's Ramblings (Melee)
---
Let's calculate the total critical damage if you are using a gun. 1.5 x 1.5 = 2.25. This means a weapon with a critical damage of 10 will now do 22.5 damage for its critical damage (add the base damage to get the total damage of the hit). I've actually tested the 225% figure myself. It is correct. Please note that Just Lucky I'm Alive is not always the best perk out of the three level 50 perks for a given weapon's DPS.

Crit Damage:
Melee - 337.5%
Non-melee - 225%

Critical Damage + Special Ammo vs Armor
No matter what difficulty you play on, the game treats the damage of your weapons the same up until the very end. This means that you will need the same amount of damage per projectile to negate the enemy's DT regardless of difficulty level.

Let's say you have a Medicine Stick, which for you does 78 dmg per bullet. You also have 225% critical damage. Let's assume you have 100% critical rate. You are using 45 Gov't SWC, which is x1.2 damage and enemy DT -6.

Medicine Stick + 45 Gov't SWC:
Weapon Damage: 78 + 175.5 = 253.5
Opponent DT: 100-6 (Bullet effect.)
(253.5 - 94) * (0.5 * 1.2) = 95.7 dmg (The 0.5 is from Very Hard penalty, and the 1.2 is from bullet effect.)

If enemy DT is 10 and your DAM (damage per projectile, not including any buffs except weapon mods) is 50, you will do 40 damage. DT can decrease your damage to a minimum of x0.2 it's normal amount. This is different if you are using ammunition that changes your damage (like hollow point or max charge). This process is convoluted, but if you are interested, there is a section after the results section that explains the process.

Because armor piercing ammo's DT effect applies before DT vs bullet damage calculation is done, using that over regular ammo helps the player jump over enemy DT. On the other hand, ammo that increases gun damage does not help the player jump over enemy DT because the extra damage effect of the bullet applies after DT vs bullet damage calculation is done. In other words, 15% damage boosting ammo is very different from -15 DT armor piercing ammo when dealing with armored targets.

Because perks that increase damage of a weapon are applied after the damage vs DT calculations are done, they are not useful for breaking through enemy armor. On the other hand, perks that increase critical damage (and by extension, critical chance) will help in that regard. Note that even things that do not break through enemy armor could increase DPS against armor. A simple example is Psycho.

Camarader-E boosts the base damage of a laser weapon. In other words, Camarader-E may help the player hop over enemy DT. This is a rare situation because non-critical-related perks and damage boosting ammunition do not to this. In addition, Camarader-E affects each projectile of a weapon, meaning it benefits the Tri-Beam Laser Rifle by a huge amount.

With Elijah's LAER which has 65 dmg (and no other perks but Camarader-E) against a Bighorner with 56 DT (ammo naturally has -2 DT effect, for a total DT of 54), I did 16 damage. Let's assume first that Camarader-E adds +5 to base damage of the weapon. We have 65+5 or 70 dmg. 70-54=16. The result matches. Let's assume Camarader-E adds +5 to damage after calculating DT vs dmg. 65 * 0.2 (we don't subtract because that would be below 65 * 0.2) = 13. If you add 5 to 13, you get 18. That's not 16.

And now to prove that Camarader-E affects every beam of the Tri-Beam Rifle: Against a Bighorner with 22 DT (again, net result 20 DT due to ammo), we get 30 damage. The rifle does 25x3 by default. If it was 30x3, then the result should be 3 * (30 - 20) = 30 damage. If it acted like the PipBoy claims, then it would be 3 * {[25 + (5/3)] - 10} = ~20 damage.

The DPS values of my chart take into account very hard difficulty level, critical chance, critical damage, ammunition types, perks, traits, chems, attack speed caps, ROF glitches, flawed damage formulas, weapons that reload one shot at a time, weapons that ignore DR/DT, and the whole nine yards. The DPS values in other parts of the wiki do not consider all the of the factors. Because we're looking at end DPS against an enemy with a certain DT, showing damage, regular DPS, critical chance, and critical multipliers is pointless.

Obviously melee and unarmed weapons cannot attack from a far distance away. A large reach with a melee or unarmed weapon is still useful, but its utility can't be calculated. Things like Gehenna's fire effect do not stack, but instead resets the timer on the effect.

Melee and unarmed weapons can use poisons. This make my calculations much more difficult because while the same poison doesn't stack in terms of damage, different ones do. While it would be technically superior to cycle through all the venoms and reapply them when all of them are used, that is a very masochistic way of playing the game. Also, consider how small the poison damage is relative to the best melee weapons. For example, Blood-Nap has 612 DPS against an enemy with 0 DT. Even if you get Bleak Venom and Cloud Kiss, Lethal down, that's 14 DPS increase. You'll have to hotkey the poisons too, otherwise the delay of pulling up the Pip-Boy and back down would cause a net loss in DPS. For the purposes of the chart below, the assumption will be that no poisons are used.

Explosive weapons are obviously able to damage more than one enemy at once at the expense of possible damage to oneself or their companions. Weapons that fall under Meltdown will cause explosive energy damage to appear when an enemy is killed. Elijah's LAER and LAER both do bonus damage to enemies in power armor and robots. This is noteworthy because high DT targets are often wearing power armor. LAER's bonus damage does not apply to NCR Heavy Troopers. If I had to estimate, I would say that the extra damage against robots and powder armor users is ~20% for 0DT enemies and <5% for 15 or 30DT enemies.

Missiles and mini-nukes come in cluster bomb varieties. Even when standing close enough to the target such that the player can take damage from the explosions once in a while, the accuracy of such ammunition is too low to be useful unless the enemy is standing next to a wall behind them. In that case the bombs will hit the wall nearby and detonate close to the target. Needless to say, highly explosive weaponry can cause massive collateral damage.

It is much easier to hold down fire with an automatic weapon compared to spam-clicking at a constant 5.5 clicks per second to maintain a good DPS on non-automatic weapons. For weapons fed a single round of ammunition at a time, I shot the weapon as soon as it got the last round in to maximize DPS. This is ver annoying to pull off in practice and is a ding against Medicine Stick.

Non-Hitscan Projectiles
There is a game bug where explosive projectiles do not do direct hit damage even when it's a direct hit outside of VATS. JIP fixes this bug.

A projectile that takes time to reach the enemy may require more leading as the enemy moves around in long range fights, making it harder to land hits outside of VATS. The time it takes to travel the distance also delays when you can start dealing damage at the initial point of the fight. The longer the fight, the less noticeable this effect is, but I doubt it is a large enough factor to matter in any situation.

## The Limits of Calculations

The attack speeds in the game are hard to calculate and glitched to some extent. Despite the wording in the game its files, ROF buffs only affect non-automatics. If ROF is too high and the player cannot click infinitely fast, the weapon may stop firing all of a sudden. This is why some weapons do not have Ain't Like That Now DPS values in the final comparison graph - since adding it to Fast Shot and Rushing Water glitches it out at 5.5 clicks per second, it cannot be the highest DPS setup for that weapon. Why 5.5 times per second? Because it's fast clicking that people should be able to sustain for some time.

To precisely figure out time to empty a clip and be ready to fire again (and by extension, ROF), I record footage of my autoclicking. In Premiere I find the ending frame and subtract it from the start frame and multiply the value by 0.16666 to get number of seconds. Then I divide it by the amount of reloads.

The damage formula listed in the combat page of the wiki is a great starting point but fails against armored targets in many situations. I could not come up with a better alternative that worked with other buffs like chems. To sidestep the issue with tricky calculations to a formula nobody understands, I used the weapon in the game against a Powder Ganger stuck on a cross in Nipton with Living Anatomy off. I had multiple hotkeys to change perks, DT, Fast Shot trait, view HP, and reset HP.

The critical chances are calculated instead of tested and using GECK information on rounds per clip, I can figure out the average amount of shots per clip that will be critical hits. Using damage values obtained from real world testing, I can figure out how much damage is done on an average clip when factoring in critical damage and chance.

The Fast Shot perk increases sway of the weapon, which can't really be calculated and quantified in any practical way. Aiming down sights reduces sway according to the wiki, but by how much is unknown.

Finally, the way the weapons glitch out when ROF is too high at 5.5 clicks per second is unpredictable. Due to this the margin of error of automatics is maybe 2-3%, while for non-automatics it goes up to 5-10%.

## Results

If you don't know what each column means, hover your cursor over the small icon at the top of the chart. The final thing to note here is that the chart assumes the enemy has 0 DR.

Weapon name Damage per second, 0 DT
Damage per second, 15 DT
Damage per second, 30 DT

.45 Auto SMG Honest Hearts 459 211 67 1.8
12.7mm SMG GRA Gun Runners' Arsenal 385 138 62 1.6
25mm grenade APWGun Runners' Arsenal 550 325 222 0.7
ww Alien blaster 308 283 262 0
A Light Shining in Darkness Honest Hearts 415 272 222 0.66
AER14 prototype 481 460 395 0.0225
All-American 241 199 141 0.035 (0.02275)
Annabelle 226 214 202 0.02
Assault carbine
(GRA) Gun Runners' Arsenal
247 134 87 0.9
Automatic rifle Dead Money 190 103 72 2.5
Ballistic fist 308 308 285
Blade of the East 281 281 251
Bozar HP Gun Runners' Arsenal 272 26 16 0.75 (0.4875)
Chance's knife 540 540 465
Christine's CoS silencer rifle¹ Old World Blues (add-on) 453 280 228 0.02
CZ57 Avenger 406 220 142 0.55
Elijah's jury-rigged Tesla cannon Old World Blues (add-on) 315 308 286 0
Esther Gun Runners' Arsenal 923 911 899 0.6
FIDO Old World Blues (add-on) 302 158 76 1.5
Wild Wasteland Fist of the North Rawr
480 480 448
Gatling laser 732 543 161 0.6
Gehenna Gun Runners' Arsenal 530 530 467
Gobi Campaign scout rifle 381 330 239 0.018
Grenade machinegun 222 165 114 1
Heavy incinerator 121 34 33 0.5
Holorifle¹ Dead Money 260 245 228 0.18
Hunting rifle 368 255 218 0.01
K9000 cyberdog gun Old World Blues (add-on) 304 129 33 1.35
Katana Gun Runners' Arsenal 358 358 311
Knock-Knock 318 318 285
La Longue Carabine 332 200 158 0.05
LAER³ Old World Blues (add-on) 810 720 647 0.096
Laser pistol²
(GRA) Gun Runners' Arsenal
216 187 106 0.1
Laser RCW 251 199 77 0.08
Laser rifle 484 563 589 0.025
Li'l Devil Gun Runners' Arsenal 448 292 196 1.08
Light machine gun 472 256 94 1.5 (0.975)
Lucky 260 163 134 0.3
Maria 336 162 113 0.2
Medicine Stick Gun Runners' Arsenal 357 253 207 0.06
Mercy 456 412 367 1.2
Minigun 392 213 131 0.65

Multiplas rifle 292 267 201 1.5
Mysterious Magnum 327 200 159 0.7
Nuka Breaker Gun Runners' Arsenal 517 517 487
Gun Runners' Arsenal
446 433 421
Paciencia Gun Runners' Arsenal 392 321 266 0.01
Q-35 matter modulator 372 360 325 0.2
Oh, Baby! 368 368 336
Plasma caster 445 428 378 0.7
Plasma Defender
(GRA) Gun Runners' Arsenal
296 277 235 0.3
Plasma pistol
(GRA) Gun Runners' Arsenal
295 246 202 0.5
Protonic inversal axe Old World Blues (add-on) 297 297 269
Ranger Sequoia 408 284 234 0.1
Riot shotgun 440 367 147 2.5
Saturnite fist super-heated² Old World Blues (add-on) 413 413 369
Service rifle 243 132 76 0.55 (0.3575)
Sleepytyme Gun Runners' Arsenal 271 64 36 1.7
Sprtel-Wood 9700 Gun Runners' Arsenal 611 491 192 0.5
Survivalist's rifle Honest Hearts 528 339 227 0.08
The Smitty Special Gun Runners' Arsenal 251 221 137 1.3
That Gun 386 215 177 0.5 (0.325)
This Machine 361 211 194 0.5
Trail carbine 229 142 117 0.06
Tri-beam laser rifle GRA Gun Runners' Arsenal 866 799 598 0.5
Two-Step Goodbye
Gun Runners' Arsenal
174 174 148
Vance's 9mm SMG 344 70 36 1.5

¹Damage over time effect is not calculated.
²Grunt fix does not affect this weapon. While a Bowie Knife is a knife used in combat, the combat knife is a specific category in the game and Bowie Knives are not in that category.
³Does not consider bonus damage against robots and non-NCR-Heavy-Troopers which use power armor.

To the right is a graph showing how a weapon/ammunition combo performs at various DT levels. To view it in full size, open the picture in a new tab. Melee weapons only show performance at 15 and 30 DT due to Pierecing Strike perk. Industrial Hand only has one data point because it ignores DR and DT. The second graph combines the best DPS of each ammo type for a weapon to make the graph more legible.

Finally, to the right is a chart showing how weapons, enemy DT, and level 50 perks interact. The green columns are DPS values with critical damage boost, purple has damage boost, and blue has rate of fire boost. Notice how the highest DPS values tend to go from Thought You Died to using Just Lucky I'm Alive as enemy DT increases.

## Conclusion

30DT = Robo-Scroption Boss
15DT = Deathclaw
0DT = Tunneler

HP ammo can actually be useful against armored targets if the weapon DAM is high enough. Generally it makes sense to switch between AP and HP ammo. Don't forget that match rounds increase accuracy.

The best level 50 perk to get for DPS is Just Lucky I'm Alive for the most part. It is the best perk for most instances and most weapons. Ain't Like That Now is a terrible choice, placing near last in every single situation. My opinion is to go for Just Lucky I'm Alive for maximum DPS or Thought You Died for good DPS and higher maximum health.

DPS Winner
The Industrial Hand is broken in how overpowered it is and you don't even need to spam click. However, it is a player-only weapon. Give Fist of Rawr! to Veronica instead. Elijah's LAER is the best for long range encounters against heavily armored enemies, but its weapon condition is very low (recall that lower than 100% CND means lower critical chance). Tri-Beam actually delivers higher DPS than Elijah's LAER at 15DT, with tied DPS at 0DT. Generally I recommend Tri-Beam over Elijah's LAER since 30DT enemies are rare, and the CND is just terrible. Esther is very high DPS, but it's a mininuke launcher and with Big Boy you will end up killing yourself half of the time. For guns, the Survivalist's Rifle is a great general gun, but the Paciencia is actually great against 30DT despite having to reload all of the time.

Old Glory vs Oh, Baby! vs Gehenna
Oh, Baby! is just terrible. Old Glory is great for those who don't want Blood-Nap despite its high DPS due to its short reach.

Blood-Nap vs Chance's Knife
Blood-Nap is simply better, even though Chance's Knife gets Grunt.

Medicine Stick vs Sequoia
Medicine Stick has far higher CND and accuracy but has lower DPS than Ranger Sequoia while being annoying to reload optimally.

Gatling Laser vs Minigun vs LMG

The lasers here deteriorate faster than the miniguns due to MC ammunition, but it's not a huge problem. LMGs on the other hand fire for days without a hitch but has low accuracy. Gatling Laser > Sprtel-Wood > Avenger > Minigun. Gatling loses some of its lead at high DT but still wins by a good margin. LMG beats minigun against 15 and 0DT but loses by a lot to Gatling.

Pistol King of the Hill
Li'l Devil is stronger than ALSID in terms of pure DPS except for 30 DT enemies. Firing Super Hand Loads, A Light Shining in Darkness has lesser CND compared to Li'l Devil, but Li'l Devil has notably lower accuracy. In terms of the king of pistols, Li'l Dvil, ALSID, and Sequoia all have their shining moments, but I think Sequoia wins out due to very high accuracy. Purely in terms of DPS, the Sequoia is for 30DT and Li'l Devil for 15 and 0DT.

12mm SMG vs .45 Auto SMG
The .45 Auto SMG has higher DPS than the 12mm SMG in all cases, but has slightly lower accuracy and much lower CND due to the use of Super Hand Load rounds. SMGs are generally very weak due to low DAM with a ROF still inadequate due to ROF buffs for non-automatics, while eating up ammo.

Annabelle vs Red Glare
Red Glare beats Annabelle except for 30DT opponents for DPS but loses in accuracy.

## Special Ammo vs DT

This section is purely academic, meaning that it has no effect on the data. So unless you want to read a bunch of useless stuff, skip this part. For the purposes of this section, assume I am talking about a character with no perks, no chems, max stats, normal difficulty, and unmodded weapons unless specifically stated otherwise. This is important.

First let's talk about the damage formula in the combat page of the wiki. DT vs DAM vs Ammo AP is calculated first, and only in the end are things like perks and ammo damage boosts (like hollow point or hand load) applied. Usually the resulting damage after DT vs DAM calculation is DAM - DT. The floor is 20% of the original DAM. There is a specific point where (DAM - DT) = (DAM * 0.2). I will just call this 'Magic DT' (the particular name isn't that important).

Let's write this out so it's easier to see what the wiki's combat page predicts.

DAM = 50
10 DT: 40 dmg (50 DAM - 10 DT)
11 DT: 39 dmg (50 DAM - 11 DT)
39 DT: 11 dmg (50 DAM - 39 DT)
40 DT: 10 dmg (50 DAM - 40 DT OR 50 * 0.2) Magic DT
41 DT: 10 dmg (50 DAM * 0.2)
1000 DT: 10 dmg (50 DAM * 0.2)

While that system makes intuitive sense, it gets weird when enemy DT is high and we are comparing ammunition types. I will show an extreme example to make things more clear.

DAM = 50
DT = 1000
AP Ammo (100% dmg, -25 AP): 10 dmg [Because: (50 * 0.2) > (50 - 1000 - 25)]
HP Ammo (150% dmg, x3 enemy DT): 15 dmg [Because: (50 * 0.2) > (50 - 3000); ((50 * 0.2) * 1.5) = 15]

If enemy DT is an insane 1000, then both HP and AP fail to penetrate armor so much, they both hit the floor (DAM * 0.2). This means any DT modifications here don't matter. The only thing that matters is the damage boost of the HP ammunition, which is calculated after DAM vs DT calculations. This means HP > AP ammunition against very high DT targets. We would also expect HP ammo in this case to hit its damage floor of 15 damage at 40 DT. This means that it makes no difference if the enemy has 40 DT or 1000 DT. The problem is that none of this is totally true.

To be clear though: If the player is not using special ammunition, the wiki's formulas are correct.

Weapon = Elijah's LAER (no mods)
DAM = 65

Ammunition: Regular microfusion cells (DT -2)
Magic DT = (65 * 0.8) + 2 = 54

Predicted Damage:
54 DT: 13 dmg Magic DT
55 DT: 13 dmg
1000 DT: 13 dmg

Actual Damage:
54 DT: 13 dmg Magic DT
55 DT: 13 dmg
1000 DT: 13 dmg

Verdict: Wiki's formula works perfectly.

Weapon = Elijah's LAER (no mods)
DAM = 65

Ammunition: Microfusion cell, max charge (DT -10, Dmg x 1.5)
Magic DT = (65 * 0.8) + 10 = 62

Predicted Damage:
61 DT: 21 [(65 - (61 - 10)) * 1.5]
62 DT: 19.5 ((65 * 0.2) * 1.5) Magic DT
63 DT: 19.5
...
1000 DT: 19.5

Actual Damage:
61 DT: 21
62 DT: 19.5 Magic DT
63 DT: 18 dmg (19.5 - 1.5)
64 DT: 16.5 dmg [19.5 - (1.5 * 2)]
65 DT: 15 [19.5 - (1.5 * 3)]
66 DT: 13.5 [19.5 - (1.5 * 4)]
67 DT: 13 dmg (Floor is 13)
...
1000 DT: 13 dmg

Verdict: Wiki's formula fails.

Remember the 'Magic DT'? If enemy DT is above the Magic DT and the player is using ammunition that changes weapon damage, the wiki's formula fails. I found a way to explain this behavior, but it fails when taking into account other buffs like perks.

Here is a group of formulas that accurately predicts damage of a weapon with ammunition with damage buffs. Note that these formulas were not tested for critical hits.

$MagicDT = (DAM \times 0.8 \times Effect_{HP}) + Effect_{AP}$

The HP Effect is 3 for 9mm HP, etc. The AP Effect is 10 for Max Charge, 5 for Optimized, 25 for 5mm AP, etc.

$Dmg_{Magic DT} = max[DAM \times 0.2, (DAM \times 0.2 \times DmgFactor_{Ammo})]$

$Dmg_{Magic DT + n DT} = max[DAM \times 0.2, (Dmg_{Magic DT} - (DmgFactor_{Ammo} \times n))]$

Ammo Damage Factor is 1.5 for Max Charge, 1.3 for Over Charge, etc. If you don't know how to read the formula above, realize that max[1, n -3] means the result is either 1 or whatever n - 3 is, picking the larger value of the two. This means (in this example) that 1 is the floor.

DAM is multiplied by 0.8 because it mathematically gives us the DT where DAM - DT = DAM * 0.2. Then, you account for the armor negation of some ammunition types by adding it to the result.

Look back at the example where I said the wiki's formula fails. Notice how the wiki's formula starts to fail after the Magic DT because Max Charge (x1.5 dmg) was used. The damage seems to be falling below the floor (predicted to be 19.5) at a rate of 1.5 damage per 1 increase in DT. x1.5 damage is the damage bonus of max charge ammo. This is not a coincidence. The damage the player does will continue to decrease by 1.5 per 1 increase in DT until it hits the floor of 13. 13 is the damage we would expect the player to do if Max Charge didn't have a x1.5 damage bonus. This is also not a coincidence.