Modern Warfare 3: How to Use Aftermarket Parts & Gunsmith Conversion Kits

Call of Duty: Modern Warfare 3 is taking weapon customization to a new level with the introduction of Aftermarket Parts. This brand-new customization option will give players something to strive for even after they’ve fully completed a weapon’s individual progress bar. Anyone who has ever maxed out every gun in Call of Duty knows how much of a grind it can be, but this is the developers’ way of sweetening the deal for each weapon you check off the list.

A semi-automatic handgun might get converted into a three-round burst with extra damage, a shotgun may go from pump-action to full-auto, or an LMG could be paired down into something far more mobile while retaining its big damage potential.

Not every weapon will have this feature, but it will still be a huge source for theory-crafting and experimentation, so if that’s your jam, there’s plenty to get excited about. Here is what you need to know about the Aftermarket Parts and Gunsmith Conversion Kits in Call of Duty: Modern Warfare 3.

Related: Modern Warfare 3 Carry Forward: MW2 & Warzone 2.0 Shared Progression Details

Modern Warfare 3: Aftermarket Parts & Gunsmith Conversion Kits Explained

Aftermarket Parts are what make the new customization options run in Call of Duty: Modern Warfare 3. As seen in the initial developer update, these parts will be used to completely remake weapons after you’ve maxed them out. In the video, we see them break down a Renetti handgun and give it a huge facelift.

Not only do the parts change, but the gun is renamed entirely to the Jak Ferocity thanks to the Carbine Kit. These kits are located behind an additional menu at the bottom of the Gunsmith, in a similar place where weapon platforms are located in Modern Warfare 2.

You can see exactly which Aftermarket Parts are required to make a Conversion Kit on this screen for the Renetti, as they’re located just underneath the kit’s description. You only need to unlock each part to gain access to the whole kit.

How to Unlock Aftermarket Parts & Conversion Kits in MW3

Aftermarket Parts are obtainable by checking off a new set of weapon challenges after you’ve reached Maximum Weapon XP on a gun that is eligible for a Conversion Kit. Similar to weapon camo challenges, these objectives will be combat-based and require you to strictly use the gun you want to upgrade.

Whether you’re getting kills in Tac-Stance, going on a big killstreak five times, or ticking off a set number of weekly objectives, each gun will have a unique goal to reach. Clearing that benchmark gives you the parts and access to the aforementioned Weapon Conversion menu.

Which Guns Will Have Gunsmith Conversion Kits?

The full list won’t be out until closer to the game’s launch on November 10, but we do have a few confirmed entries, and they add beautiful new depth to an already expansive system. These early entries run across weapon classes, but they give us a good idea of the kinds of changes to expect

Base Weapon	Conversion Kit	Challenge
Pulemyot LMG	Bullpup Kit	Get 25 Kills while hip-firing or using Tac-Stance.
Renetti Handgun	Carbine Kit	Get 30 Kills with five attachments equipped.
WSP Swarmwith (UZI)	Akimbo Kit	Unlock via weekly challenge in the preseason.

So much of the conversation around Multiplayer and Warzone weapons has been around customization over the last few years, and while some players were already overwhelmed by the introduction of Weapon Tuning in Modern Warfare 2, the devs are sending a pretty clear message with this one. They’re all-in on making Call of Duty more customizable, and the gameplay will reflect that in the new era.