150 Round Box Mag attachment in MW4
The 150 Round Box Mag is a magazine attachment (“150-round box magazine”) that community sites list for one weapon: FiNN LMG. CODMunity lists a stat change on 1 of them; the largest is magazine size +50% on the FiNN LMG (better). It is in 2 popular builds that CODMunity lists.
Community-reportedDMZ Radar, ggranked, and CODMunity, read . Unverified, not Activision data.
Weapons that can equip the 150 Round Box Mag
Activision publishes no compatibility list; 3 community sources report this weapon. No weapon level is reported.
| Weapon | Class | Weapon level | Stats with a listed change |
|---|---|---|---|
| FiNN LMG | LMG | magazine size (large, better), total rounds (large, better), reload time (large, worse), crouch movement speed (small, worse), ADS out speed (small, worse), ADS movement speed (small, worse), firing movement speed (small, worse), and ADS speed (small, worse), and 5 more |
What the 150 Round Box Mag changes
Percent changes are relative to the base value with nothing attached (CODMunity, read November 4, 2026).
| Weapon | Stat | Base | With it | Change |
|---|---|---|---|---|
| FiNN LMG | Magazine size | 100 rounds | 150 rounds | +50% (better) |
| Reload time | 6270 ms | 7587 ms | +21% (worse) | |
| ADS movement speed | 2.03 m/s | 1.93 m/s | −5% (worse) | |
| ADS speed | 400 ms | 420 ms | +5% (worse) | |
| Movement speed | 4.38 m/s | 4.25 m/s | −3% (worse) | |
| Sprint speed | 5.82 m/s | 5.65 m/s | −3% (worse) |
Smaller changes are left out of the table: 7 other stats on the FiNN LMG.
How it ranks among magazine attachments
Its largest change on each weapon, compared with the other magazine attachments the source lists that stat for.
- FiNN LMG: its large magazine size change (better) is the best of 2 magazine attachments.
Pros and cons the sources list
None reported, which is different from having none.
Popular builds that use the 150 Round Box Mag
CODMunity lists 2 popular builds that use it, all for DMZ. The styles are Long Range and Apex Attachment. The same builds also use optic, muzzle, barrel, stock, and rear grip attachments.
| Weapon | Mode and style | Tier | Other attachments | Builder |
|---|---|---|---|---|
| FiNN LMG | DMZ, Long Range | Not tiered | Optic: KV Corsac Holo, Muzzle: FSS IS300, Barrel: TT Seongun 508mm, and Stock: Hanbit Tech50 Gen.5 | Open in the builder: FiNN LMG, Long Range |
| FiNN LMG | DMZ, Apex Attachment with Apex Attachment | Not tiered | Optic: KV Corsac Holo, Muzzle: FSS IS300, Barrel: TA N-VCX 18", and Rear Grip: FTAC R7 Wrap | Open in the builder: FiNN LMG, Apex Attachment |
Builds are community-reported and unverified.
Frequently asked questions
What does the 150 Round Box Mag do in MW4?
CODMunity lists 13 stat changes for it across 1 weapon: 2 better and 11 worse. The largest is magazine size +50% on the FiNN LMG (better).
Which weapons can use the 150 Round Box Mag?
Community sites list FiNN LMG. Activision has not published a compatibility list.
Is the 150 Round Box Mag in a popular build?
Yes. CODMunity lists it in 2 popular builds, on FiNN LMG.