Thanks sgtt. Problem solved (maybe).
A little investigation into the "gift" of 45 ACP dies.
Here are the components I received (and after closer inspection - have a better understanding for):
1. Lee carbide sizing die. Set that aside for use at another time.
2. RCBS FL sizing die without decapper/expander, even though it is drilled and tapped for one.
3. RCBS decapper/expander/neck belling die that is NOT a sizing die. I didn't know.
4. RCBS bullet seating die.
The expander in the decapper is 0.4485" in diameter, which will be sufficient to tightly hold the bullets as soon as the brass is resized, which it is NOT.
I called Dave and he found the "missing" decapper/expander for the FL sizing die.
All is right again in my reloading world.
Now the question is, why does RCBS make a decapper/expander/neck belling die that does not resize the case?