Even with the Micrometer screwed down tight when the press ram and shell holder are fully raised, I have about 1/8" unsized.
Read the instructions, if I was not warned the die would not neck size all of the neck I would ask for my money back. If it is necessary to purchase another die to size the neck I would need recommendation, I have neck sizing dies, my neck sizing dies do not have case body support, the nice part about my neck sizing dies, they have threads. Threads make it possible to adjust the amount of neck sizing I want, and if I decide to go into bushing die sizing I can use the bushing die without the bushing then finish with a neck sizing die.
F. Guffey