7.62x51 L43A3 blank

Hi all,

I recently came across a new ‘L’ number code (new to me anyway!) for the current British issue 7.62mm blank - L43A3.

The L43A3 came about in 2014, as I have a L43A1 and L43A3 both with 2014 dates.
There doesn’t seem to be much of a difference, they both weigh the same (both empty and live cartridges), the only physical difference I can see is that the crimps are shorter on the L43A3 (right, second picture) with the L43A1 (left, second picture) having long ‘deep’ crimps. This seems a rather loose reasoning to change the ‘A’ number, so I would assume there’s something else at play to change the nomenclature. Has anyone come across the L43A3 before?
There doesn’t seem to be anything on the L43A3 anywhere!

Best regards,

Simon