Are you referring to 7.7mm Japanese (Arisaka)? If so, here's a link that should help you out: http://www.reloadersnest.com/frontpa...?CaliberID=217

Looks like the .30-06 can be used to form brass, but the base diameter is a little smaller than the 7.7mm. Takes 0.311" bullets like the .303 British and the 7.62x54R Russian cartridges, which are available. Looks like Norma also still makes brass, which would provide a better fit than reformed .30-06 brass.

Good luck.

Mike