the palms as it's called on Moose antler, is so porous and pithy it looks like a sponge inside ,,,big air cells
Well all depends on the circumstances - I've got some moose palms - yes I know what they are that are completely solid - and HARD.
Like most antler - so much depends on: whether the antler came off a live animal or were drops, how old - whether living or dropped, etc.
With moose you'll also find a difference in where it came from - eastern moose, shiras - those found in the Rockies, or the big western Canadian and Alsakan breed. Shiras for instance, have relatively small horns and almost all I've seen when fairly fresh has been quite solid as compared to their eastern and northern brethern
Elk antler, including the tines, is normally somewhat to very much porous, yet I've had frsh elk antler tines that were as solid as most sambar stag. On the other hand I've had sambar that had a 1/4 hole up the center, and so on. One of my favorites is mule deer, usually very solid, but again it all depends on when and where it was aquired. Most antler available these days is drops and so much depends on how quickly after dropping they are picked up i.e. how old they are.
FWIW in some 35 years of working with antler I've learned there really is no hard and fast rules - the only way I know for sure is cut into it and find out..