The goal of the project was to produce a .338 caliber cartridge with magnum level performance that would fit in a compact, short action rifle.
The .338 RCM is conceptually similar to the WSM cartridge family, but is somewhat smaller dimensionally.
[2] Like the .338 caliber cartridges which predated it, the round is designed for hunting medium to large sized North American game.
As Ruger intended the cartridge to be chambered in short bolt-action rifles,[3] they trimmed the .375 Ruger parent case to 2.015 in (51.2 mm) to ensure a comparable cartridge overall length to the .308 Winchester.
This allowed Ruger to chamber the cartridge without extensively redesigning their M77 rifle.