I just read an article on this in Am. Rifleman. Apparently they couldn't get the ballistics they wanted with the 338 bullet so they tried the .323.
The result is a cartridge that equals the 338 win mag in performance and even begins to surpass it out around 400 yards.
This really has my attention. The only drawback is the limited number of bullet selections you have even as a handloader. I am very seriously considering getting this caliber in either a Browning micro hunter or hunter.