
| Type | Dummy, MK 100 |
|---|---|
| Projectile | steel, aluminum windscreen, blue, 1 copper driving band Projectile Markings: (white ink) 20MM DUMMY RND FOR GUN MK 12 (stamped on fuse) 1211649-A-1 Driving Band Markings: 20-MM MK.11-0 A LOT 26-AFP |
| Case | steel, choke crimp, cadmium plated, 6 holes Markings: (black ink) RNO 1-228 |
| Primer | none |
| Headstamp | 20MM-MK5. MOD.0 RNO . 8 . 64 |