I have been sorting through a box of about 25 loose 20mm projectiles. I have been able to assign them all to their proper case types except fot the 3 shown below. I realize these scans are not very good, but they should serve to show the pertaint features.
I will list only the important diminisions to ID these. If anyone needs a complete set of diminisions, let me know.
#1–O/A-89.47mm; From bottom of driving band to tip-80.28mm; From bottom of driving band to juncture of nose cap-56.34mm; Nose cap-25.03mm.
#2–O/A-78.49mm; From bottom of driving band to tip-66.15mm; From bottom of driving band to juncture of nose cap-44.02mm; Nose cap-22.12mm.
#3–O/A-74.64mm; From bottom of driving band to tip-65.14mm; From bottom of driving band to juncture of nose cap-39.90mm; Nose cap-25.63mm.
I have compared all of these to numerious examples in my collection of 20x102 Vulcan, 20x110 Oerlikon RB “S”, 20x110 Oerlikon HS404 and 20x110 USN. These do not match anything I have in any of these case types.
Some more details.
#1 is plain steel and is hollow and has a gray nose cap. Stamped on the side is MK3-11-J-LOT-203. No other markings
#2 is plain steel with a bright aluminium nose cap which I can not remove. I assume it has a cavity. It does have a base cavity for a tracer element. Trere are no markings of any kind.
#3 is black steel with a non-removable black aluminium nose cap. It feels like it is a solid steel ball but the nose is flat (4.73mm) and appears to be filled with some type of rubber compound. Also, as can be seen in the scan this projectile is more pointed with a longer nose cap than any other 20mm I have seen. Again, no markings of any kind.
Any help to ID these will be appreciated.