wood bat ?

Gin,
There are a variety of ways that composite wood bats are made, not limited to...

-composite handle bolted and glued together with a wood barrel (demarini)

-wood bat wrapped with fiberglass sheets (louisville and easton)

-wood bat partially hollowed and refilled with lighter compressed shafts of wood and epoxy

Generally the objective is added durability as opposed to improved performance. Most of these bats seem to perform about on par with the better grade wood bats. You are correct in that there is less rebound in wood and wood composite bats than there is in hollow metal and composite bats.
BBCOR regulations, in effect, take much of the rebound out of those hollow bats, bringing the performance closer to wood.

Some also are put together like wooden pieces of a pie, glued together, then sanded so it looks like a solid piece of wood, sometimes with a meal shaft at the core. They can be extremely durable.

thanks