7mm-08 Remington

The 7mm-08 Remington is a rifle cartridge that is almost a direct copy of a wildcat cartridge developed around 1958 known as the 7mm/308. As these names would suggest, it is the .308 Winchester case necked down to accept 7 mm bullets with a small increase in case length. Wikipedia
 
Bullet diameter0.284 in (7.2 mm)
Case length2.035 in (51.7 mm)
Neck diameter0.315 in (8.0 mm)
Overall length2.80 in (71 mm)
Base diameter0.470 in (11.9 mm)
Rim diameter0.473 in (12.0 mm)