The principle at work in the short magnum cartridge is the fitting of larger volumes of powder in closer proximity to the primer's flash hole, resulting in more-uniform ignition.

The .300 WSM also head-spaces off of the case shoulder, versus the older .300 Winchester Magnum's belted head space design.

The advantage to this round is the ballistic performance is nearly identical to the .300 Winchester Magnum[2] in a lighter rifle with a shorter action burning 8 - 10% less gunpowder.

Also, in small ring actions the larger chamber diameter removes more steel from the barrel tenon, making it weaker radially.

The .300 WSM is adequate for hunting all big game including (but not limited to): moose, black bear, brown bear, elk, mule deer, and white-tailed deer in forests and plains where long range, flat shots are necessary.