Some commercial pilots are hardened and can be a buggar to downsize without some Knowledge/experience with different cutting tools especially with hobby sized equipment. I don't know why they go to the trouble to harden them because the light use & wear conditions they are subjected too, they don't need to be. I have built many different pilots for my own use with just a regular bolt as the donor piece, mild steel shafting will work as well but you will get a little better final cut finish on the better quality steel (less drag by the brass neck while being turned over the pilot).
Just cut the major dia ( your neck bore size) and then "carefully" cut the much smaller shank dia last using small cuts otherwise they "pigtail" twist quite easily then you have to start over...not a big thing as your cost is absolutely nothing but your time.