The Zayne is a 378 Weatherby Improved. The parent case was a 378. The Zaylea Ann will be a 340 Weatherby Improved. The parent case is a 340.
I was able to take out body taper, shorten the neck, and improve the shoulder.
The 378 Weatherby holds 120 +/- 5 grains of h20. The Zayne holds 144. Best part of using Weatherby actions and brass is your getting excellent components without breaking the bank. Also the cartridge has a belt which makes life easy for the shooter. If you run out of handloads you can stop by the nearest sporting goods store and pick up a box of factory ammo. Keep your brass and now you hunted while you fireformed.