Building brass for 7.63 Mannlicher pistol

Attachment 247824Decided that I wanted one of these neat looking 1901/1905 7.63 Mannlicher Argentine pistols. I started experimenting with forming brass, after a few false starts [.300 blkout doesn’t work] I tried using .30 carbine brass. Running them through a lee .339 sizer to start with and then into a .30 carbine die I’m getting brass that’s 3-5 thousands over what the mannlicher brass is supposed to be. My pistol is still in route to my ffl guy, should be there next week what with the storm and all. But my question is has anyone else tried this route to make 7.63? Another question, since I’m cutting the carbine brass back to .840, what is the thinnest wall .30 carbine brass available?
Here’s one that I’ve swaged down but need to shorten it.

Very cool pistol! Where did you find it?

Found it on the Simpson Ltd website. If you’re looking for something odd they might have it.

https://www.rccbrass.com/7-63mm-mannlicher/
He dearly loves his brass but if you have to get some to work up some loads...
https://www.buffaloarms.com/7-63-man...licher-7-63man
A little better but still pricey and currently out of stock.
But....a pearl is in the picture...

Buffalo Arms uses 32-20 Starline brass. That cartridge is notorious for thin case walls from every manufacturer and turning a rim down is actually pretty easy even if its just chucked in an electric drill and a file used to create a new rimless case...

Good luck on getting her back into shooting form.

Bruce