Reconsidering my caliber selection for this new rifle. The 375 H&H would be a good caliber for this action, ammo is readily available here in Alaska. Another caliber I have been considering and reading up on is the new 400 H&H, which is based on the 375 H&H case. This caliber could be a viable option as well. Has anyone heard about whether or not ammo is available yet or had experience using this caliber? The more I think about it, from the information I read on the internet the 400 H&H would be a great round for hunting brown bear here in Alaska. Any thoughts on this new caliber?