Practical cats are usually a simple neck down of highly available brass.
.20-223, 7mm-300Win, Bushing dies complete the picture

Conversions of the H&H case were numerous, 308 Norma, .30-338 come to mind
Usually shortening it to fit into the more commonly available .30’06 length magazine.

Much more Practical . Loaded to higher pressures, they met velocity goals.

History May Not Repeat, But it Rhymes.