Call of Duty Season 3 Week 7 challenges unlock regenerating Carbon 57 mag

The Carbon 57 just got the kind of magazine that can change how aggressive players build an SMG. Week 7’s challenge set unlocks the Fabricator Mag, a reward that regenerates ammo when you stop firing, and that instantly makes the Carbon 57 harder to starve out in the middle of a push.

That matters because the Carbon 57 was already a strange kind of contender. It launched as a full-auto SMG at Player Level 46 with a 50-round magazine, a very high ammo count, respectable range and recoil, and below-average damage for its class. On paper, that made it a steady, forgiving close-range gun, but not one that screamed for a build-changing attachment. The Fabricator Mag changes that calculation by giving the weapon a way to keep feeding itself without a reload, which is exactly what aggressive players want when a fight turns into a chain of broken plates, armor swaps, and instant re-challenges.

Raven Software’s May 14 patch notes officially listed the Fabricator Mag as a Weekly Challenge Reward, and the timing lines up with a 24-challenge Week 7 set split evenly across Co-Op Campaign and Endgame, Multiplayer, Zombies, and Warzone. Complete any 6 of those 24 tasks and the mag is yours. That is a much shorter grind than clearing the full board, which makes the attachment feel like a real mid-season target instead of a distant completion prize.

The attachment first surfaced in the Season 03 Reloaded content drop, which launched on Thursday, April 30, 2026 at 9AM PT. Raven also used that same patch cycle to push the Carbon 57 a little closer to the center of the close-range meta, cutting recoil deviation by 15% in the April 21 Warzone Season 03 notes. Put together, the message is pretty clear: the studio has been tuning the gun for fast-handling pressure, then handing out a magazine that rewards exactly that style.

Season 03 Reloaded also added the MK.78 Lightframe PDW Conversion, Warden 308 Badlands Pistol Kit, and Ryden 45K Apex Sweeper Rig as weekly-challenge attachments, but the Carbon 57 reward stands out because it does more than tweak numbers. It gives SMG players a way to stay on target, stay in the fight, and keep moving without stopping for a reload at the worst possible second. That is the sort of attachment that can reshape a close-range build, and Week 7 made it available fast enough that nobody grinding the season has to wait long to find out.