FSS Moodkiller attachment in MW4
The FSS Moodkiller is a muzzle attachment (“Light Silencer”) that community sites list for 2 weapons: Astaroth .57 and Signal 50. CODMunity lists a stat change on 2 of them; the largest is damage range −11% on the Signal 50 (worse). It is in 2 popular builds that CODMunity lists.
Community-reportedggranked and CODMunity, read . Unverified, not Activision data.
Weapons that can equip the FSS Moodkiller
Activision publishes no compatibility list; 2 community sources report these 2 weapons. No weapon level is reported.
| Weapon | Class | Weapon level | Stats with a listed change |
|---|---|---|---|
| Astaroth .57 | Sniper Rifle | damage range (moderate, worse) | |
| Signal 50 | Sniper Rifle | damage range (moderate, worse) |
What the FSS Moodkiller changes
Percent changes are relative to the base value with nothing attached (CODMunity, read November 4, 2026).
| Weapon | Stat | Base | With it | Change |
|---|---|---|---|---|
| Astaroth .57 | Damage range | 100% | 90% | −10% (worse) |
| Signal 50 | Damage range | 100% | 89% | −11% (worse) |
Changes across weapons
The stats it changes on 2 weapons, with the lowest and highest change.
| Stat | Weapons | Lowest change | Highest change | Verdicts |
|---|---|---|---|---|
| Damage range | 2 | −11% | −10% | 0 better, 2 worse |
How it ranks among muzzle attachments
Its largest change on each weapon, compared with the other muzzle attachments the source lists that stat for.
- Astaroth .57: its moderate damage range change (worse) is the weakest of 2 muzzle attachments.
- Signal 50: its moderate damage range change (worse) is the weakest of 2 muzzle attachments.
Pros and cons the sources list
None reported, which is different from having none.
Popular builds that use the FSS Moodkiller
CODMunity lists 2 popular builds that use it, all for Multiplayer. The styles are Sniper and Mobility. The same builds also use optic, barrel, rear grip, stock, and laser attachments.
| Weapon | Mode and style | Tier | Other attachments | Builder |
|---|---|---|---|---|
| Astaroth .57 | Multiplayer, Sniper | Very good | Optic: Schlager 7x, Barrel: FTAC Crosswind 30", Rear Grip: FJX S-TAC Grip, and Stock: Usenko V8-LKR | Open in the builder: Astaroth .57, Sniper |
| Astaroth .57 | Multiplayer, Mobility | Very good | Optic: Schlager 7x, Barrel: FTAC Crosswind 30", Stock: Usenko V8-LKR, and Laser: Schlager VISIV-5 | Open in the builder: Astaroth .57, Mobility |
Builds are community-reported and unverified.
Frequently asked questions
What does the FSS Moodkiller do in MW4?
CODMunity lists 2 stat changes for it across 2 weapons: 0 better and 2 worse. The largest is damage range −11% on the Signal 50 (worse).
Which weapons can use the FSS Moodkiller?
Community sites list Astaroth .57 and Signal 50. Activision has not published a compatibility list.
Is the FSS Moodkiller in a popular build?
Yes. CODMunity lists it in 2 popular builds, on Astaroth .57.