I know my post didn’t make much sense so let me try to clarify.Partitions ?
They are using a partitioned bullet with a tin core and a tin jacket plated with nickel. They chose the lightest of the material for both the jacket and the core which doesn’t make much sense to this knuckle dragger. A more interesting design to me would be a copper bullet with a tin frangible front end, so the copper would add a little bit of weight and better penetration.
But then again I’m just a dumb knuckle dragger.