Having so elegantly disposed of Dum-Dum Southern Circuit, the question now remains ?Who and Where and When?
Further pointers>>>Primer Diameter: Italian 7,7 cases have a .250" Berdan primer ( same as British)…Primer Annulus colour is correct for British made cartridges, but Italian??; This cartridge looks like a .217" Berdan primer???
The Neck Crimp is also correct for British-made Cartridges up to the mid- 1940s… NO ( or indistinguishable) Primer Crimp, so therefore not likely to be an Aircraft use 7,7/.303.
Now “French or ???”…Not having seen many French made .303s ( 7,7) to compare with, but knowing the French had detailed headstamps, one could propose another maker…the Czechs, maybe or even the Spanish or Estonians?
or Finns ( Sako?)
BTW, what is the source of this cartridge case?? (Mixed Milsurp of Eastern European origin, or otherwise?) And since there is no year date, is it actually “military” or just a “commercial FMJ?”
And I assume the propellant is Nitro-cellulose? What type (Flake or Tubular?)
How many questions there are to be answered…just like a Forensic Post Mortem!!!