Call Of Duty: Modern Warfare 3 Season 4 - All Week 4 Challenges (2025)

Call of Duty: Modern Warfare 3's fourth season has released a new aftermarket part this week, unlocked upon completing any five of this week's challenges. Each core playlist—Multiplayer, Zombies, and Warzone—has seven challenges each. If you complete five challenges from any playlist (or a mix of playlists), you'll get your hands on the latest aftermarket part.

This week, completing these challenges will unlock the JAK Thumper for the RGL-80, which makes this the first launcher in MW3 to have attachments. Let's go over how this attachment works and showcase all 21 challenges added in this set of Weekly Challenges for MW3.

Week 4 Challenge Reward

Upon completing any five challenges this week, you'll unlock the JAK Thumper-656 KIt for the RGL-80. This effectively enables the use of ammunition attachments on the RGL-80 at the cost of ADS speed and sprint-to-fire speed.

While this conversion kit is equipped, you'll have access to three unique attachment options:

• 40mm Slug: This projectile is a two-hit kill anywhere on the body, but it no longer explodes.
• 40mm Sticky: The projectile sticks to a surface and detonates after a short delay.
• 40mm Drill Charge: The projectile sticks to a surface, burrows through it, then explodes.

Multiplayer Challenges

Tips

• Stun and Flash Grenades are required for the first challenge.
• You can typically find explosive ammo options for shotguns and sniper rifles.
• Consider using mines for the kills-after-death challenge.
• Play Hardcore for easy grenade multikills.

Zombies Challenges

Tips

• The first three challenges require MWZ ammo types. These are awarded from Contracts, Infested Strongholds, and can be crafted if you have the right schematic.
• Counter UAVs always spawn at Mercenary Camps.
• Use the MW3 Gladiator or Karambit for the melee kills challenge.

Warzone Challenges

Tip

• The loot cache challenges must be completed on Urzikstan.