I have found several of these spent rounds on the same former British island. The headstamp containsFN 65 and a circled plus sign on it. It looks like the top was crimped, but why is it extended and squeezed together on all of these spent rounds?
In the on-line table I see that FN translates to "FN Fabrique National d’Armes de Guerre, Herstal BELGIUM" and is the 65, 1965?
Thanks for any info.