Rick,
The information in the chapter on solids also applies to expanding bullets, mostly because at least one solid (the Swift Break-Away Solid), essentially "lightly" expands. Then there's the Woodleigh Cup Point.
There are also monolithic "softs" designed to lose their petals, essentially turning into solids--and monos that expand to greater and lesser degree.
Essentially what we have today is a continuum from solids that do not expand, to solids that expand a little, to "softs" that expand a little more, to softs that expand very widely, or even come almost completely apart. They all operate under the same basic principles, to greater and lesser degrees--including cavitation, stabilization, etc.
