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!

The datum line is irrelevant, it doesn't apply when forming a case like this. You'll be necking down to create a false shoulder. Push it back a little at a time to where there's a little resistance closing the breech.....not much, not like with a bolt action, just enough to feel it.

Got it. The first few came out looking good. Thank you.