on the 4th one are the ends antler - nice work on all 5 been a member of a couple years - finally sent a post - Mike
Straight mandrels work well for cork and threaded mandrels for wod is the best way to go. Backlash tools has both kinds of mandrels. They have a lot of rodbuilding specialty tools. Also Mudhole and Anglers Workshop have mandrels.
Moose is the easiest because it has thicker bone area. Other antler types have to be very close to final diameter or you will cut into the pithy area.
I shed hunt and have friends who also shed hunt so that is where I get most of mine. You can buy deer and elk antler parts, but they usually are not cheap. The moose you pretty much have to shed hunt for or have friends that do.