5.8x21mm Armor Piercing attachment in MW4
The 5.8x21mm Armor Piercing is a ammunition attachment that community sites list for one weapon: X-58 Nyx. CODMunity lists a stat change on 1 of them; the largest is bullet penetration +50% on the X-58 Nyx (better). No popular build that CODMunity lists uses it.
Community-reportedggranked and CODMunity, read . Unverified, not Activision data.
Weapons that can equip the 5.8x21mm Armor Piercing
Activision publishes no compatibility list; 2 community sources report this weapon. No weapon level is reported.
| Weapon | Class | Weapon level | Stats with a listed change |
|---|---|---|---|
| X-58 Nyx | SMG | bullet penetration (large, better) |
What the 5.8x21mm Armor Piercing changes
Percent changes are relative to the base value with nothing attached (CODMunity, read November 4, 2026).
| Weapon | Stat | Base | With it | Change |
|---|---|---|---|---|
| X-58 Nyx | Bullet penetration | 9.0 in | 13.5 in | +50% (better) |
How it ranks among ammunition attachments
Its largest change on each weapon, compared with the other ammunition attachments the source lists that stat for.
- X-58 Nyx: its large bullet penetration change (better) is the best of 2 ammunition attachments.
Pros and cons the sources list
None reported, which is different from having none.
Popular builds that use the 5.8x21mm Armor Piercing
No popular build listed by CODMunity uses the 5.8x21mm Armor Piercing. That says nothing about how it performs; most listed attachments are in no popular build.
Frequently asked questions
What does the 5.8x21mm Armor Piercing do in MW4?
CODMunity lists 1 stat change for it across 1 weapon: 1 better and 0 worse. The largest is bullet penetration +50% on the X-58 Nyx (better).
Which weapons can use the 5.8x21mm Armor Piercing?
Community sites list X-58 Nyx. Activision has not published a compatibility list.
Is the 5.8x21mm Armor Piercing in a popular build?
No. None of the popular builds that CODMunity lists uses it.