Weapon attachments have seen a revamp in Modern Warfare 2.

It is unlocked by levelling weapons in multiiplayer. However, unlike previous games, Modern Warfare 2 asks you to use and level multiple weapons to unlock all of its various attachments.

There’s a bit of complexity to this new unlock and customisation system, so this guide will delve into and explain how to unlock attachments, how to use the new Weapon Tuning feature, and more.

On this page:

How the Gunsmith and customising weapons works in Modern Warfare 2

Once you reach level four in multiplayer, you’ll have access to custom loadouts, and the ability to manually equip, level and customise weapons via the Gunsmith.

  • How the Gunsmith and customising weapons works
  • How to unlock attachments
  • How to unlock attachments quickly using Weapon Vaults and Blueprints
  • How to unlock and use Weapon Tuning in Modern Warfare 2

The Gunsmith is a menu where you’ll be spending a lot of time should you desire to emphasise your playstyle and weapon choice with various enhancements.

To access this menu, go to the ‘Weapons’ tab on the main multiplayer menu, select the first option - ‘Multiplayer Loadout’ - and pick whichever loadout you want to customise the weapon of.

Once in the loadout screen, a selectable option will appear above either of the weapons you have equipped - select this to customise the weapon.

This will then take you to the Gunsmith screen, where you can pick and equip individual attachments for each part of the gun, up to a maximum of five.

Each weapon has its own attachment availability, with some weapons having their own bespoke attachments, such as Bolts on bolt-action rifles.

Initially, when a weapon is at level one, its attachment slots will be locked - as you use and increase its level, those slots will open up and allow you to swap in and out your desired attachments.

You can also swap out your equipped Receiver in the Gunsmith screen too, allowing you to change the weapon’s type between what’s available in its same Platform. (We have more on Platforms and Receivers in our how to unlock all weapons explainer.)

Bear in mind however that changing the Receiver may remove attachments which are not compatible with other Receivers - the game will notify you of this when browsing the other Receivers.

If a weapon cannot be customised with any attachments, it’ll instead take you to the ‘Customize’ tab, where you can customise your weapon with various weapon skins - known as camos - charms, stickers and more.

If you’d like to learn more about how to customise weapons via camos, be sure to check out our guide on how to unlock the Gold camo.

How to unlock attachments in Modern Warfare 2

Unlocking attachments for weapons works in one of two ways - Universal attachments and Platform-specific attachments.

Let’s go through these one by one:

  • Universal attachments are, once unlocked, apply to every weapon in the game, consisting of:
  • Muzzle
  • Underbarrel
  • Ammunition
  • Laser
  • Optic
  • Platform-specific attachments unlock only for weapons within that Platform, consisting of:
  • Barrel
  • Magazine
  • Stock
  • Rear Grip

For Universal unlocks, though it will apply to every weapon once available, it still might require a specific unlock path - for example, the M4 has an Optic which requires you to level the .50 GS handgun to level 4 first.

  • Muzzle

  • Underbarrel

  • Ammunition

  • Laser

  • Optic

  • Barrel

  • Magazine

  • Stock

  • Rear Grip

Platform-specific attachments also encourage you to interchangeably use several of its available weapons within that Platform - but are more limited to that platform.

This requirement is shown below an attachment’s name when hovering over it in the weapon customisation screen - you can see this in the image below:

As a result of the above, many attachments will be locked until you reach the required level with a specific weapon that is most likely not the one you’re using.

Also know that some weapons don’t have access to every type of attachment, and others can have their own bespoke type of attachments - in those cases, the attachments are unlocked by levelling weapons within the same Platform as itself.

How to unlock attachments quickly using Weapon Vaults and Blueprints in Modern Warfare 2

As well as individual attachment unlocks, there are two (albeit specific) ways to unlock things at once through Weapon Vaults and Blueprints.

Weapon Vaults in Modern Warfare 2 immediately unlock an entire Platform’s weapons and attachments, and all share the same aesthetic and theme, similar to Blueprints in previous releases.

At launch, the only available Weapon Vault in Modern Warfare 2 is the FJX Cinder, available to players who own the Vault Edition.

This particular Weapon Vault fully unlocks the M4 Platform and its associated weapons and attachments, all stylised with a black and red theme.

Though no others have been confirmed, signs point towards this potentially being an earnable Battle Pass reward or in-game store purchase.

With a Weapon Vault, Weapon Platform-specific attachments are unlocked for use immediately.

Universal attachments however will remain inaccessible until they are unlocked normally - this will mean levelling the associated weapon to unlock the attachment.

If you own either a Weapon Vault or Blueprint, its themed attachments are available to swap out on every weapon compatible with that attachment via the attachment skins menu, shown in the image below.

Additionally, with a Weapon Vault, there’s no need to level a weapon to access its attachment slots - they’re available right away too.

However, the weapon’s level will remain at the level it was before acquiring a Weapon Vault one - this means for features such as Weapon Tuning, you’ll still have to reach the weapon’s maximum level to have access to it.

Getting stuck into multiplayer? We explain the best guns in Modern Warfare 2 and how to unlock all weapons and attachments - as well as individual pages on putting together an MP5 loadout, FTAC loadout, M4 loadout, Kastov 762 loadout, SP-R 208 loadout, TAQ 56 loadout, 556 Icarus loadout, Vel 46 loadout, M16 loadout and FSS Hurricane loadout.

At launch, you might be wondering where the Battle Pass and Hardcore Tier 1 modes are, as well as how to claim Modern Warfare 2 Twitch drops.

Elsewhere, learn how to turn off crossplay on PlayStation and Xbox, get and use Double XP, level up fast, get gold camo, check KD and unlock all MW2 Operators.

Playing the story? We have explainers on how long the Modern Warfare 2 campaign is and all safe code combinations.

How to unlock and use Weapon Tuning in Modern Warfare 2

Note: After being disabled in the days following launch, weapon tuning was re-enabled on Friday, 4th November:

To unlock Weapon Tuning for a specific weapon, you must reach the maximum level of that weapon.

This feature - new to Modern Warfare 2 - allows you to tweak the individual statistics of tunable attachments available for each gun.

For example, if you’re using the M4 and equip it with the underbarrel Edge-47 Grip, you’re able to edit positive and negative stats to tweak it to your liking - you can adjust the weight and length of the grip to affect its various statistics.

To access this, head over to the Gunsmith menu, equip an attachment and, if it can be customised, a ‘Tune’ button will appear - select this to customise the attachment’s attributes.

You’ll reach a screen with a radar graph, a couple of sliders and various information about the equipped weapon.

As you move each slider, increasing or decreasing a stat, it’ll boost one whilst lowering the other - this is visible on the radar graph.

By increasing the grip’s weight, it’ll boost recoil stabilisation, but lower Aim Down Sights (ADS) speed - and vice versa if decreasing the weight.

If you increase the grip’s length, it’ll improve the weapon’s aiming idle stability whilst lowering your aim walking speed - and it’ll do the opposite if decreasing the length.

This is a more in-depth feature to delve into once you start to hone in on your desired build and playstyle with the gun in question.

As mentioned, this feature unlocks when you level up a gun to its maximum possible level, but the specific level varies based on the number of levels per weapon - the max level of a weapon can be seen on the weapon selection screen, or its associated Platform tree.

If you’re looking for the best weapons to pair with the weapon tuning feature, be sure to check out our best guns guide, or if you want to know how to level up fast, we have a guide on that too.