All MW3 Aftermarket Parts & how to unlock them
ActivisionEach MW3 and Warzone season brings new Aftermarket Parts that can completely change how the best guns work.
Season 5 brings six new attachments, reintroducing unique AW weapons such as the Blunderbuss Shotgun with a Barrel Conversion Kit, bringing the total number to over 30.
Here’s how to unlock every Aftermarket Part, all the compatible weapons, and what they do.
How to get MW3 & Warzone Conversion Kits
Most Aftermarket Parts, also called Conversion Kits, can be unlocked via Armory Unlocks, in which players have to complete a specific number of multiplayer, Warzone, or Zombies challenges.
Some are available through the Battle Pass or the Weekly Challenges system, where players need to complete five multiplayer, Warzone, or Zombies challenges for a specific seasonal week.
Every Aftermarket Part in MW3 & Warzone
Season 5
| Aftermarket Part | Unlock method | Compatibility | Description |
|---|---|---|---|
| JAK Widemouth Barrel | Complete five challenges from Season 5 Week 1 | MORS | Resembling CoD AW and WWII’s Blunderbuss, provides the MORS Sniper Rifle a widemouth barrel designed to hold “magnetic ball projectiles” that expand upon firing. |
| JAK Slash | Complete five challenges from Season 5 Week 3 | Weapons with underbarrel capabilities | Vertical grip that functions as a combat knife, replacing your melee attack with a “lethal slash.” |
| JAK Protean | Complete five challenges from Season 5 Week 4 | RAAL MG | Gives the RAAL a “telescoping barrel” with full-auto and semi-auto fire options. |
| JAK Cataclysm | Complete five challenges from Season 5 Week 2 | RPK | Equips the RPK LMG with.50 Cal ammunition while retaining its high-capacity drum mag. |
| JAK Deathmarch | Complete five challenges from Season 5 Week 6 | BAL-27 | Replaces the standard ammunition with high-voltage power cells and equips a photonic scatter barrel. |
| JAK Devastators | Complete five challenges from Season 5 Week 8 | Reclaimer 18 | Allows you to wield two Reclaimer 18 Shotguns at the same time. |
The Season 5 Reloaded update expands the Aftermarket Parts roster with the JAK Deathmarch and JAK Devastators.
The JAK Devastators were supposed to arrive in Week 7 but Sledgehammer confirmed they’ve been pushed back to Week 8, the final week before Season 6, the last season before Black Ops 6, arrives.
Season 4
| In-game look | Aftermarket Part | Unlock method | Compatibility | Description |
|---|---|---|---|---|
 | JAK Gunslinger | Complete five challenges from Season 4 Week 7 | Basilisk | Allows the Basilisk revolver to carry eight rounds of .357 ammunition, increases its rate of fire, and grants “near-instantaneous” trigger action |
 | JAK Volkh | Complete five challenges from Season 4 Week 6 | KV Inhibitor | Stock and receiver mod that grants two-round burst with minimal dispersion |
 | JAK Decimator | Get 30 Suppressed SMG Kills | Lachmann Shroud | Lets the Lachmann Shroud fire in full auto mode |
 | JAK Intimidator | Get 15 headshots with Sidearms (Pistols) | Renetti | Turns the Renetti into a single-shot weapon |
 | JAK Thumper-556 | Complete five challenges from Season 4 Week 4 | RGL-80 + other Launchers | Shoots projectiles at higher velocities and distances |
 | JAK Scimitar Kit | Complete five challenges from Season 4 Week 3 | FJX Horus | Unlocks a “high-capacity drum mag” as well as improved range and recoil control |
 | JAK Requiem | Complete five challenges from Season 4 Week 2 | Kastov 762 + Kastov 545 | Grants a system designed to “eliminate vertical recoil” |
 | JAK Harbinger Kit | Complete five challenges from Season 4 Week 1 | M4 | Turns the M4 into a deadly Rifle chambered in .50 Cal ammo with a slow fire rate, bullet velocity, and “significant increase in recoil.” |
Season 3
| In-game look | Aftermarket Part | Unlock method | Compatibility | Description |
|---|---|---|---|---|
 | JAK Shadow Titan Kit | Reach Level 25, activate the Armory Unlock, and complete eight Daily Challenges | Bruen Mk9 | Converts the Bruen Mk9 into a compact, suppressed light support weapon |
 | JAK Jawbreaker | Reach Level 25, activate the Armory Unlock, and complete eight Daily Challenges | KV Broadside | Converts the KV Broadside Shotgun into an automatic Battle Rifle |
 | JAK Cutthroat | Reach Level 25, activate the Armory Unlock, and complete eight Daily Challenges | MCW, MTZ, M4, and AMR9 | 3D-printed stock that provides speed and stability while ADS |
 | JAK Revenger Kit | Reach Level 25, activate the Armory Unlock, and complete eight Daily Challenges | BP50 | Conversion Kit that gives the BP50 a shortened receiver and high-capacity magazine |
 | JAK Wardens | Reach Level 25, activate the Armory Unlock, and complete eight Daily Challenges | Lockwood Mk2 | Turns the Lockwood Mk2 into the iconic Model 1887 Akimbo Shotguns |
 | JAK Atlas Kit | Reach Level 25, activate the Armory Unlock, and complete five Daily Challenges | AMR9 | Converts the AMR9 into a 5-round burst weapon chambered in 556 |
 | Photonic Charge Barrel | Get the MORS, reach max level and get 100 one-shot Kills | MORS | A hyper-advanced barrel that changes the fire nature of the trigger hold and release to let off a high-powered shot |
 | JAK Patriot | Reach Level 25, activate the Armory Unlock, and complete eight Daily Challenges | M16 | Turns the M16 into a fully automatic rifle featuring a heavy ported barrel built to provide better recoil control and aim stability |
Season 2
| In-game look | Aftermarket Part | Unlock method | Compatibility | Description |
|---|---|---|---|---|
 | JAK Burnout | Reach Level 25, activate the Armory Unlock, and complete three Daily Challenges | Holger 26 | Enables a specific firing mode with a significantly higher fire rate, and risk of overheating leading to increased spread |
 | JAK Tyrant 762 Kit | Reach Level 25, activate the Armory Unlock, and complete five Daily Challenges | Longbow | Replaces the receiver and magazine to support 7.62 BLK ammunition, transforming the gun into a “harder-hitting weapon” |
 | JAK Limb Ripper | Reach Level 25, activate the Armory Unlock, and complete eight Daily Challenges | Several weapons | Equips an underbarrel chainsaw for quick melee kills. |
 | JAK Maglift Kit | Reach Level 25, activate the Armory Unlock, and complete five Daily Challenges | Haymaker | Strengthens the magwell, bolt, and trigger assembly to support the use of an oversized drum magazine |
 | JAK Glassless Optic | Reach Level 25, activate the Armory Unlock, and complete three Daily Challenges | Several weapons | A compact reflex optic without glass which provides a sharp and unobstructed view |
 | JAK Backsaw Kit | Reach Level 25, activate the Armory Unlock, and complete five Daily Challenges | Holger 556 | Enhances the maneuverability involving the complete removal of the stock |
 | JAK Outlaw-277 Kit | Reach Level 25, activate the Armory Unlock, and complete eight Daily Challenges | BAS-B | Transforms the BAS-B into a lever-action rifle, reducing its firing speed but significantly improving accuracy |
Season 1
| In-game look | Aftermarket Part | Unlock method | Compatibility | Description |
|---|---|---|---|---|
 | JAK Purifier | Reach Level 25, activate the Armory Unlock, and complete five Daily Challenges | MTZ-556, Holger 556, DG-56, SVA 545, RAM-7, MTZ-762, BAS-B, Sidewinder, Riveter | An underbarrel flamethrower |
 | JAK Headhunter Carbine Conversion | Reach Level 25, activate the Armory Unlock, and complete five Daily Challenges | Rival-9 | Turns the Rival-9 into an Assault Rifle with “three-round burst” |
 | JAK Bullseye | Reach Level 25, activate the Armory Unlock, and complete two Daily Challenges | Most weapons categories | Compact dot Optic that provides a clear and precise sight picture |
 | JAK Beholder Rifle Kit | Reach Level 25, activate the Armory Unlock, and complete five Daily Challenges | TYR | A long and heavy barrel that increases range, recoil control, and damage range, transforming the gun into a single-shot Rifle |
 | JAK Signal Burst | Reach Level 25, activate the Armory Unlock, and complete three Daily Challenges | Rival-9 | Grants the Holger 556 four-round bursts |
 | JAK Ettin Double Barrel Kit | Reach Level 25, activate the Armory Unlock, and complete five Daily Challenges | AMR9 | Creates a pair of stacked barrels that fire simultaneously, resulting in double the damage |
 | JAK BFB | Reach Level 25, activate the Armory Unlock, and complete eight Daily Challenges | Many Assault Rifles, Submachine Guns, Battle Rifles, Marksman Rifles, and Sniper Rifles | Minimizes recoil while notably amplifying muzzle sound |
 | JAK Thunder LMG Kit | Reach Level 25, activate the Armory Unlock, and complete five Daily Challenges | Sidewinder | Features a high-capacity magazine and progressively increases its firing rate |
What do MW3 & Warzone Aftermarket Parts do?
Aftermarket Parts are attachments unlocked separately from Weapon Rank – usually through a challenge. These can be as simple as a new Muzzle or Optic, or a Conversion Kit that completely changes how a weapon behaves.
These attachments can improve weapon stats such as range, damage, and recoil control, transform a weapon’s category by converting an Assault Rifle into a powerful SMG or heavy LMG, and provide better sight or mobility with specific accessories like Optics or Stocks.
Why are Aftermarket Parts important?
Aftermarket Parts have become an important feature due to their impact on MW3 and Warzone’s meta weapons. Some can even turn underrated weapons into meta contenders or popular picks, requiring several nerfs to balance them.
If you’re interested in unlocking more content through grinding, check out how to unlock the Spilled Beans camo and all the upcoming events that offer free rewards.