New (to me) 7.62 NATO short range bullet variation

Both these bullets were pulled from italian 7.62 NATO ammo with the same hds “SMI + 85”

On the left the typical short range bullet with brass solid body and plastic tip. On the right a strange variation ( at least to me) with “stepped” ends.

This bullet was not modified, it was simply pulled from the case. Now, does anyone have some info about this variation?

Background info:

The steps on the boattail will most probably have a de-stabilizing effect (due to so-called Magnus moment) when the bullet slows down. The yaw will increase dramatically, leading to a much larger air drag which in turn reduces range.

The two steps immediately after the plastic nose will increase wave drag during bullet flight at high speeds.