Cut down 43 Mauser brass...Any clues?

[xsiv4s]

I have some custom Dominion 43m brass that was cut down and it looks like it was sized to a 44 cal. I've been searching the internet but nothing seems on point, does anyone have an idea what this might be. It came from Bob Hayley's estate and he reloaded it; so, it is probably something pretty obscure.

 

[4060MAY]

41 Swiss ?
my Vetterli requires .440 bullets, I converted to CF and use 8mm Lebel brass to make cases