I have no idea whether (or even if) the extruded 175 Partitions have changed.
If you include the Solid Bases, there are at least two generations of Ballistic Tips. As I noted earlier, some of the Ballistic Tips developed when they appeard in the 1980s have evidently not been changed, while others have.
The problem with adding a plastic tip to an already existing soft-point bullet is the big hole necessary for the insertion of the tip. This essentially turns the soft-point into a HUGE hollow-point, which expands more violently. I would guess (but don't know for sure) that's what happened when Hornady first introduced the SST--which was essentially a boat-tailed Interlock Spire Point with a tip added.
