Overbore Capacity
A cartridge whose case capacity is disproportionately large relative to the bullet diameter it fires, trading high velocity for faster throat wear.
The .220 Swift, .264 Win Mag, .26 Nosler, and .28 Nosler are all classic overbore cartridges. They achieve high velocities by burning a lot of powder behind a relatively small bullet, but the propellant-to-bore ratio cooks the throat faster than balanced cartridges.
Practical barrel life on extreme overbores can be 1,000 to 2,000 rounds before throat erosion makes the rifle inaccurate at distance. Balanced cartridges like 6.5 Creedmoor and .308 Winchester can run 3,000-5,000 accurate rounds.