20 x 102mm United States
Details
| Type | SAPHEI |
|---|---|
| Projectile | steel, aluminum windscreen, yellow with red and black bands, 1 copper driving band |
| Case | aluminum, choke crimp, greenish grey anodized Markings: (black ink) 20MM M103 AL ACN 87K000E004 |
| Primer | none |
| Headstamp | [none] |
| Notes | This was made by Olin in the late 1980s for marketing aluminum-cased cartridges as a weight-saving measure for aircraft. Projectile is inert. |