.338 Marlin Express

The .338 Marlin Express is a new cartridge developed by Marlin Firearms and Hornady. It is based on the .376 Steyr with a goal to duplicate the venerable .30-06 Springfield's performance in a cartridge compatible with lever-action firearms. Wikipedia
 
Case length47.90mm
Parent case.376 Steyr
Bullet diameter.338 in (8.6 mm)
Neck diameter9.45mm
Rim diameter13.92mm