The .300 Lapua Magnum (7.62×70mm) is a rimless, bottlenecked, centerfire cartridge developed for long-range rifles.

The common rifling twist rate for this cartridge is 240 mm (1 turn in 9.45 inches), with 4 grooves.

Land width is 4.47 mm and the primer type is large rifle magnum.

[3] The high pressures involved mean that the .300 Lapua Magnum should only be chambered in rifles that are specifically designed for extremely high-powered cartridges.

A rifle that theoretically could safely be chambered for the 94.5 mm long .300 Lapua Magnum is the bolt-action SAKO TRG-42.

Due to the large case capacity in relation to the bore diameter (known as overbore) the .300 Lapua Magnum is harsh on barrels and typically wears them out in 1,000 to 1,500 rounds.