Anyone load this? I just got a nicely customized Martini Cadet in this cartridge. With it, I got brass, bullets, RCBS dies, and some loaded ammo.

Do I just use my FL sizer to neck down the 218 brass to the datum line, then fire form? Looks like that is what the previous owner was doing.

I have 500, 25gr Hornady HP's to play with. The previous owner was using 4198. Any better powder suggestions? Any help on this is appreciated. Thank you!