Hmmm ... this after receiving my 338-06AI a couple of weeks ago. A least I haven't started the 411 Hawk/Whelen yet.

Federal Announcement (Page 4)

Cape•Shok® .370 Sako Magnum
Big game hunters looking for a new caliber offering heavy bullets will love the .370 Sako
Magnum. Federal Premium® will load a 286-gr Barnes® Triple-Shock X-Bullet option, as well as
a 286-gr Nosler® Partition® offering. Like its European counterpart the 9.3x66mm Sako
Magnum, the new .370 Sako Mag provides excellent stopping power and is a great choice for
hunting large game at shorter distances.
Features & Benefits
• 30-06 necked up to a .366 caliber
• High energy
• Standard action allows for more rounds in magazine
• Heavy bullets for additional stopping power
Part No. Description
P370B 370 Sako Mag 286-gr Nosler Partition
P370C 370 Sako Mag 286-gr Barnes Triple-Shock X-Bullet

If you search the Medium Bore forum, there have been a few posts about it. Its the American version of the 9.3x66 Sako. They ditched the original (I want to say about 4 years old now) metric name and stuck "magnum" on it to sell to America. Potent cartridge, thats for sure, a wee bit more oomph then the 9.3x62 but not as much as the 9.3x64 Brenneke.

IN a 9.3x62 sized to fit in an 06 length action the bullet lines up with the shoulder. While the 9.3x66 has a nice gain in gross capacity the net gain is the small area between the bullet and case wall. To make use of the longer case you need a 3.6" magazine. Don't go sell your 9.3x62.
Marketing at its best.