20 x 102mm United States
Details
| Type | Inert, M55 |
|---|---|
| Projectile | steel, aluminum windscreen, black, 1 copper driving band Projectile Markings: (white ink) 20MM BALL M55 FAX20-2559 Driving Band Markings: *HVM-20-65 54 20MM T283E1* |
| Case | steel, choke crimp, cadmium plated Markings: (black ink) INERT INERT |
| Primer | electric, flat, brass, 3-stake crimp, black |
| Headstamp | [none] |
| Notes | Inert case filler. |