I have done the same thing and made creedmoor brass from LakeI have resized a few hundred 308 cases to Creedmoor just by removing the bushing from my Redding FL S die. It will leave a nice flair to the case mouth so you will "feel" it when you lower your ram on the press. What worked best for me was sizing a little, spin the case, size a little, spin the case, etc. After this, I trim and run them in a standard FL die and turn the necks. Plenty of work but when using Lapua Palma brass you end up with ....... the just released Lapua 6.5 Creedmoor brass.
I never thought Lapua would make the stuff but glad they did. I doubt highly my barrel would outlast the Lapua cases I made though.