I have to make brass for my .17Ackley hornet from .22hornet brass....I start by neck sizing the brass with my bullberry die to .20 then .17 I have the die set so it sets the neck to the correct depth where the shoulder will form.
I then put it through my.17AH full length die to get correct size on neck for bullet and also this double checks the shoulder so it will chamber.
I then anneal the brass and do a reduced load by 1grain of powder add a bullet and fire it... the case fireforms to the chamber and we have .17ah brass.... I can do 100 cases in about an hour and I get about 10 reloads from them.

I also reload the .17 grain bullets from kranks for fireforming an shoot bunnies/crows or just plink with them. at £5 a hunded fro the bullets I can reload cheaper than .17hmr ammo