7mm Remington Magnum

The 7mm Remington Magnum rifle cartridge was introduced as a commercially available round in 1962, along with the new Remington Model 700 bolt-action rifle. It is a member of the belted magnum family that is directly derived from the venerable .375 H&H Magnum. Wikipedia
 
Bullet diameter.284 in (7.2 mm)
Case length2.5 in (64 mm)
Case capacity82.0 gr H2O (5.31 cm3)
Parent case.375 H&H Magnum
Base diameter.512 in (13.0 mm)
Overall length3.29 in (84 mm)
Rim diameter.532 in (13.5 mm)