
| Type | HEI |
|---|---|
| Projectile | steel, brass fuze, olive drab over red, 1 copper driving band Projectile Markings: (stamped) EMPTY Driving Band Markings: MM-2-49 52 20MM M87 |
| Case | brass, knurled choke crimp, 2 holes Markings: (stamped) EMPTY |
| Primer | none |
| Headstamp | 20MM M21A1 LC 52 |
| Notes | This is an inert board dummy. It has two small holes in the case near the shoulder for attaching to a display board. There is also a small hole drilled in the fuze. |