Odd .45 ACP round ID

This is from an inquiry in another website forum asking for ID. No information beyond pictures, and the headstamp appears to be WRA 45 Auto, but not sure about that. I don’t remember seeing anything like it. Armor piercing???

This is a round from the “Salvo Squeeze Bore” (SSB) project.
These are multipe cone shaped projectiles to be fired through a squeez bore barrel.

There is plenty of info on these here on the forum (use the search function) and also in the web.

Here a good summary on the 9x19 version by Lew:

These should be the .45/.38 SALVO squeezebore trials, no?


Edit: beat me on the line, Alex

See HWS Vol. III page 29 for a drawing of the projectile stack and other information about this cartridge.

photo of the box