Originally Posted by
country gent
How about a shortened 223 case cut to same length as 30 carbine and expanded up to 357 dia (basically a 9X23 wildcat type cartridge) for the bullets you want to use. Would have the rimless desighn you want, WOuld be fairly easy to make with a file trim die and die set, Brass is very plentifull and inexpensive, and it would have the heavier rifle type case head. Basically Cut and file to rough length in file trim die, expand to .357 caliber deeper than bullet seats. Final trim load and fire form.