for fire forming new brass heres what I do its the easiest no brainer way

for example Im gonna explain this with the use of 308 win just for examples sake
1. I full length size the brass, I feel you should always resize even new brass.
2. Trim brass to just under Maximum length, if the brass measures less then skip this step.
3. Then load as normally using a start charge of a selected load depending on your desired powder, primer and bullet. I use whatever extra powder or primers I have around and bullets Im not gonna use anymore or just a cheap package of winchester power points.
4. have a fun day of plinking, now you will have your fire formed brass ready for neck sizing.
IMO dont even bother with any other fire froming method they are just asmuch work if not more than throwing together some plinker loads. besides shooting blanks aint asmuch fun as sending some lead down range. you may even shoot at paper you never know you may just have an accurate plinker/fire forming load.