Ruger precision Rifle

[zimagold]

Generally speaking, the 3 listed calibers all have similar 308ish case capacity, as the bore size is reduced you generally need a longer barrel to achieve a similar level of powder burn / gas expansion.

Edit: I used generally twice as this is impacted by multiple factors including powder burn profile and projectile resistance in the bore.

Fundamentally the rifle is an expansion chamber with the volume being set based on bore diameter and length.