"Call me curious, I went to the Handloader's Manual of Cartridge Conversions by John Donnelly.
Oddly enough, there are two versions shown.
The first is a rimless case, pretty close, dimensionally, to a 22-06.
The other is rimmed, and made by shortening a 9,3x74R case.
Both take a .228" bullet according to the book. Both fire a 70gr bullet around 3000fps."