ID 20MM Shell?

20 MM shell…
Trainer, as projectile is one piece to casing, casing is drilled with holes…
Markings are on head stamp…
“20MM MK2 1943”, with little L like symbol in diamond.
Side of brass part of projectile tip, flat, not pointed.
At least it looks like that…Any idea? US? Weapon?
Thankyou, Andy


Sounds like a plain vanilla 20 mm Oerlikon. The “brass part” is the fuze. There were several recent threads on 20mm Dummy and/or Drill rounds that you might want to look at.