With yearly releases, Call of Duty needs to change things up to keep it fresh. One of the new features in Modern Warfare 3 is Aftermarket Parts and Conversion Kits.
These parts and kits allow CoD players to transform their favorite weapons into new threats. They increase the overall variety in the game, but unlocking them is far from easy. You’ll need plenty of XP in the process, so save up those double weapon XP tokens and start gaming.
Here’s all there is to know about Aftermarket Parts and Conversion Kits in MW3.
How to unlock Conversion Kits in MW3
Aftermarket Parts and their Conversion Kits are unlocked through challenges once a weapon reaches max level. If you’re looking to upgrade your weapon with Conversion Kits, you’ll first need to get it to max level just to unlock its respective slots.
The fastest ways to level up guns should speed up this process, and you’ll also need to complete certain challenges to unlock the Conversion Kits that will go into the slots that share the same name.
These challenges are often part of Weekly Challenges each week throughout MW3’s seasons, so get ready to log on every Wednesday to unlock the latest and greatest addition.
What are Conversion Kits in MW3?
Conversion Kits are attachments that transform a weapon while defying the laws of physics. Conversion Kits completely change the weapon at times, like the JAK Ferocity Carbine Kit for the Renetti, which turns it from a burst pistol into an SMG.
New Conversion Kits will be added throughout each season, mostly through weekly challenge completions. But remember, to use a Conversion Kit on a specific weapon, that weapon must be max level.
It’s worth grinding every gun in the game to maximize their level because new Aftermarket Parts will be added over time, and you never know which one will be overpowered at launch and take over the meta when it releases.
These new parts and attachments unlock all sorts of cool stuff like new optic sights, a part that turns a shotgun into a full-auto battle rifle, or even an underbarrel chainsaw like something out of Gears of War. Yeah, let’s have some fun.
Here are all the Aftermarket Parts and weapon kits currently available in MW3.
Aftermarket Parts and Conversion Kits in MW3 season zero
JAK Raven Kit (MCW)
“Versatile and modular, this .300 conversion of the MCW can be adapted to hit hard in nearly every combat scenario.”
- How to unlock: Season zero, week one challenge
JAK Heretic Carbine Kit (MTZ-762)
“This powerful, 7.62 AR was crafted to deliver exceptional damage with moderate recoil.”
- How to unlock: Armory Unlock
Broodmother .45 Kit (WSP-9)
“A high-damage conversion kit that rides the line between SMG and AR with hard-hitting .45 Auto rounds.”
- How to unlock: Armory Unlock
JAK Annihilator Bullpup Kit (Pulemyot 762)
“A modified, bullpup LMG that provides superior maneuverability while still delivering heavy and consistent fire.”
- How to unlock: Armory Unlock
XRK IP-V2 Conversion Barrel Kit (COR-45)
“This carbine conversion kit for the COR-45 allows for optics and underbarrel attachments. It also introduces binary fire which effectively doubles the fire rate.”
- How to unlock: Armory Unlock
JAK Ferocity Carbine Kit (Renetti)
“This heavy carbine kit converts the Renetti pistol into a compact and maneuverable SMG. Allows for optics, stocks, and underbarrel attachments.”
- How to unlock: Armory Unlock
JAK Nightshade Rifle Kit (DG-58 LSW)
“A 5.8x42mm assault rifle that hits hard and doesn’t ask questions. In the right hands, this rifle can win almost any engagement.”
- How to unlock: Season zero, week two challenge
WSP Akimbo Brace Stock Kit (WSP Swarm)
“A brace stock used to keep the weapon stable when firing akimbo.”
- How to unlock: Season zero, week three challenge
MCW 6.8 Full Auto Conversion (MCW 6.8)
“Converts the MCW 6.8 into a full-auto marksman rifle.”
- How to unlock: Armory Unlock
Cronen INTLAS MSP-12 (Optic)
“A quick and snappy dot optic with an integrated laser for added accuracy”
- How to unlock: Armory Unlock
INTLAS CAS-14 (Optic)
“This 2.5x optic is ideal for medium ranges and comes with an integrated laser.”
- How to unlock: Armory Unlock
Aftermarket Parts and Conversion Kits in MW3 season one
JAK Purifier
“Equip an underbarrel flamethrower” on the MCW, MTZ-556, Holger 556, DG-56, SVA 545, RAM-7, MTZ-762, BAS-B, Sidewinder, and Riveter.
- How to unlock: Season one battle pass
JAK Headhunter Carbine Conversion (Rival-9)
“Rival Assault Rifles with this three-round burst conversion kit that excels at midrange combat.”
- How to unlock: Season one, week one weekly challenge
JAK Bullseye (Optic)
“Very low-profile dot Optic. Limited interference from framework offers an exceptionally clear sight picture.”
- How to unlock: Season one, week two weekly challenge
JAK Beholder Rifle Kit (TYR)
“A long and heavy barrel that offers the best increase to range. Improves recoil control and damage range, converting this Handgun into a single-shot Rifle.”
- How to unlock: Season one, week three weekly challenge
KR INTLAS LSJ-3 (Optic)
“A 4x optic with an integrated laser for faster targeting and accurate results.”
- How to unlock: Season one, week four weekly challenge
JAK Signal Burst (Holger 556)
“A conversion kit designed for accuracy and controllability with four-round bursts.”
- How to unlock: Season one, week five weekly challenge
The Ettin (AMR9)
“Available for the AMR9 SMG, this kit creates two stacked barrels that fire simultaneously. This offers twice as much down-range damage at the cost of some accuracy.”
- How to unlock: Season one, week six weekly challenge
JAK Thunder LMG Kit (Sidewinder)
Dominate lanes and hold objectives with this LMG conversion kit for the Sidewinder Battle Rifle that brings a large capacity magazine and ramps in fire rate the longer you hold down the trigger.
- How to unlock: Sector A21 in the season one battle pass
JAK BFB
A compensator attachment for “many Assault Rifles, Submachine Guns, Battle Rifles, Marksman Rifles, and Sniper Rifles.”
- How to unlock: Sector A21 in the season one battle pass
Aftermarket Parts and Conversion Kits in MW3 season two
JAK Burnout (Holger 26)
“Gives the Holger a select fire mode called JAK Burnout that provides a dramatically increased fire rate but can overheat and expand the barrel, introducing spread.”
- How to unlock: Season two battle pass
JAK Tyrant 762 Kit (Longbow)
“This caliber Conversion Kit swaps out the receiver and magazine to accommodate 7.62 BLK ammunition for a harder-hitting, subsonic weapon.”
- How to unlock: Season two, week one weekly challenge
JAK Limb Ripper (underbarrel)
“Unrivaled at creating close-quarters carnage, this underbarrel chainsaw makes quick and messy work of anyone foolish enough to stand in your way.”
- How to unlock: Season two, week two weekly challenge
JAK Maglift Kit (Haymaker)
“This weapon modification reinforces the magwell, bolt, and trigger assembly to accommodate the extra-large drum magazine.”
- How to unlock: Season two, week three weekly challenge
JAK Glassless Optic (optic)
“This small, glassless reflex optic offers a crisp and clear sight picture for snappy target acquisition.”
- How to unlock: Season two, week four weekly challenge
JAK Burnout Kit (Holger 26)
“Introduces an adverse fire functionality that pushes the weapon to extreme fire rates but hurts accuracy as the barrel overheats.”
- How to unlock: Challenge in Sector B21 of season two battle pass
JAK Backsaw Kit (Holger 556)
“A Conversion Kit focused on making the Holger 556 more maneuverable. The stock is removed entirely for faster, more agile tactics.”
- How to unlock: Season two, week six weekly challenge
JAK Outlaw-277 Kit (BAS-B)
“This Conversion Kit transforms the BAS-B into a lever-action rifle, slowing fire rate but vastly improving accuracy for deadlier precision.”
- How to unlock: Season two, week seven weekly challenge
Aftermarket Parts and Conversion Kits in MW3 season three
JAK Shadow Titan Kit (Bruen Mk9)
“Converts the Bruen Mk9 into a compact and integrally suppressed light support weapon chambered in 300 blackout.”
- How to unlock: Season Three, week one weekly challenge
JAK Jawbreaker (KV Broadside)
“Converts this Shotgun into a hard-hitting, automatic Battle Rifle.”
- How to unlock: Season Three, week two weekly challenge
JAK Cutthroat (Stock)
“This 3D-printed stock provides an unrivaled combination of speed and stability while aiming down sights.”
- How to unlock: Season Three, week three weekly challenge
JAK Revenger Kit (BP50)
“This conversion kit turns the BP50 into a CQC legend. A 9mm caliber conversion with shortened receiver and high-capacity magazine.”
- How to unlock: Season Three, week four weekly challenge
JAK Wardens (Lockwood Mk2)
“Relive the glory days, stir up the hornet’s nest, and take down your enemies, leaving no loose ends with these museum-worthy akimbo lever-action shotguns.”
- How to unlock: Season Three, week five challenge
JAK Atlas Kit (AMR9)
“Converts the AMR9 into an extremely lethal and accurate 5-round burst carbine chambered in 556.”
- How to unlock: Season Three, week six challenge
JAK Patriot (M16)
“Converts the M16 into a fully automatic rifle with a heavy ported barrel built to provide superior recoil control and firing aim stability.”
- How to unlock: Season Three, week seven challenge
Photonic Charge Barrel (MORS)
“This hyper-advanced barrel is more than simply a barrel. Holding the trigger charges the rifle and releasing fires a single, high-power energy projectile.”
- How to unlock: Reach max weapon level with the MORS and get 100 One-Shot, One-Kills
Aftermarket Parts and Conversion Kits in MW3 season four
JAK Harbinger Kit (M4)
“This .50 cal converson kit for the M4 is an extremely deadly, quick-kill weapon. The slow fire rate, drop in bullet velocity, and a significant increase in recoil will require a careful hand.”
- How to unlock: Season four, week one weekly challenge
JAK Requiem (Kastov 762)
“A counter-balanced rifle system designed to completely eliminate vertical recoil.”
- How to unlock: Season four, week two weekly challenge
JAK Scimitar Kit (FJX Horus)
“Improved range and recoil are standard with this aftermarket kit which also unlocks the use of a high-capacity drum mag for the FJX Horus.”
- How to unlock: Season four, week three weekly challenge
JAK Thumper-656 (RGL-80)
“An improved long barrel for an infantry-carried grenade launcher. Fires projectiles at higher velocities and distances. Compatible with a wider variety of launcher projectiles.”
- How to unlock: Season four, week four weekly challenge
JAK Volkh (KVD Enforcer, KV Inhibitor)
“A meticulously crafted stock and receiver modification that updates the weapon to fire a two-round burst at minimal MOA dispersion, making every trigger pull count.”
- How to unlock: Season four, week six weekly challenge
JAK Gunslinger (Basilisk)
“A frame and cylinder conversion that allows the revolver to hold eight rounds of .357 ammunition with an exceptional increase to rate of fire and a near instantaneous trigger action.”
- How to unlock: Season four, week seven weekly challenge
Aftermarket Parts and Conversion Kits in MW3 season five
JAK Widemouth Barrel (MORS)
“A widemouth barrel crafted to accommodate magnetic ball bearings that shatter upon firing, creating a barrage of small and lethal projectiles.”
- How to unlock: Season five, week one weekly challenge
JAK Cataclysm (RPK)
“Command the battlefield with this .50 Cal conversion kit for the RPK,” Activision said. “Slow yet powerful with a high-capacity drum mag, this kit is your enemy’s nightmare.”
- How to unlock: Season five, week two weekly challenges
JAK Slash (Various weapons)
“This underbarrel vertical grip doubles as a combat knife, replacing your melee attack with a lethal slash.”
- How to unlock: Season five, week three weekly challenges
JAK Protean (RAAL MG)
“This conversion kit turns the RAAL into a highly adaptable prototype weapon with a telescoping barrel that can be toggled between full-auto and semi-auto fire, offering suppressive fire and precision in the same weapon.”
- How to unlock: Season five, week four weekly challenges
JAK Deathmarch (BAL-27)
“Replaces standard ammo with high-voltage power cells and the barrel with a photonic scatter barrel to fire a spread of lethal laser blasts that take down enemies at short range.”
- How to unlock: Season five, week five weekly challenges
JAK Devastators (Reclaimer 18)
“Dual wield shotguns.”
- How to unlock: Season five, week eight weekly challenges
Aftermarket Parts and Conversion Kits in MW3 season six
JAK Salvo (KATT-AMR)
“A sniper modification that fires anti-materiel explosive rockets that deal significant explosive damage.”
- How to unlock: Season six, week one weekly challenges
This article will be updated when more Aftermarket Parts and kits are added to MW3.
