My research interests range across the broad topics of technology, coaching, teaching, learning, and volleyball. The .300 Winchester Magnum is a magnum cartridge designed to fit in a standard rifle action. Bullet weights of 10.713.0 grams (165200gr) are the preferred choices for these game species. (It may well vary.) While environmental factors such as altitude and ambient air temperature affect trajectory, their effect is relatively minor. Copyright 2023 ShootersCalculator.comALL rights reserved. defines the common rifling twist rate for this cartridge as 254mm (1 in 10in), 6 grooves, lands = 7.62mm (0.300in), grooves = 7.82mm (0.308in), land width = 2.79mm (0.110in), and the primer type is large rifle magnum.