Warzone ISO 45 Loadout & Unlock Guide | Slow-Firing/High-Damage SMG

The UMP45 SMG from Modern Warfare 2 (2009) is returning to CoD for Season 4 of Modern Warfare II (2022), but for licensing reasons it's now called the ISO 45. Here is how to unlock the ISO 45 in MW2 and Warzone 2, as well as the best loadout for the weapon.

Warzone ISO 45 UMP45
The Warzone ISO 45 is Season 4's SMG. | © Activision Blizzard

Warzone and MW2 Season 4 introduces two new guns. One of them is a jack-of-all-trades AR, and the other is a high-damage SMG called the ISO 45 (based on the UMP45). Here is how the devs describe the new SMG:

...known for its lightweight design and decent fire rate for short- to midrange engagements. Its higher-caliber rounds make it a heavy-hitter compared to its fast-firing counterparts.

Does it sound like an SMG you're going to want? Then keep reading to find out how to unlock the ISO 45. We've also provided the best Warzone loadout for the ISO 45!

Warzone 2.0 & Modern Warfare 2: How To Unlock The ISO 45 (UMP45)

You get the ISO 45 as a reward for completing Battle Pass Sector D19 of the Season 4 Battle Pass. This will require 15 Battle Pass Tiers to unlock. You could buy the BlackCell version of the Battle Pass, which gives you 25 Battle Pass Tiers to spend immediately, but this option will cost more. If you just grind the Battle Pass normally, then it will take you about four or five hours of play to unlock.

The Best Attachment Setup For The ISO 45 In Warzone 2

I So 45 Season 4 Loadout
This is a great all-around loadout for the ISO 45. | © Activision


MuzzleFTAC Castle Comp
Barrel9" PTX Trainer
Laser1MW Quick Fire Laser


Slimline Pro

45 Round Drum

This SMG has a horrible iron-sight, which is why we got rid of it for a 1x. The ISO 45 also has a lot of recoil, so for the best loadout we're taking a very efficient recoil-mitigation attachment: the muzzle brake. The extended magazine doesn't need explaining in Warzone, but you might be wondering why we took this specific laser. It provides a great ADS-speed boost, but crucially it doesn't produce a visible laser.

The Best Loadout For The ISO 45: Secondary, Perks & Equipment

Secondary: M4

Warzone 2 Season 4 Meta M4 Loadout
The M4 is really good for Resurgence. | © Activision

Especially for Resurgence, we highly advise the M4 right now, which is fantastic at mid-range combat. This couples wonderfully with the ISO 45 for more aggressive players.

Perks (Base, Bonus & Ultimate)

These are our favorite perks:

Base Perk

Bomb Squad, Overkill

Bonus PerkFast Hands
Ultimate Perk


You can play a bit more loose in pubs, but for Ranked we always go with Ghost. And then alongside Ghost we've gone for a very typical selection. Bomb Squad allows us to survive a few more nades, Overkill lets us take the Cronen with the ISO 45, and Fast Hands allows us to swap weapons more quickly.

Equipment (Lethal & Tactical)

For our equipment choice:





We aren't going to recommend anyone abuse the Drill Charge, so we've taken the ever-reliable Semtex grenades instead. And for our Tactical we went with smokes, for some extra survivability.

  • It will be a lot easier to unlock the ISO 45 if you have a copy of MW2!

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