We all have to remember that in many states, the .30 Carbine will not meet the power factor to be legal to hunt with in that state and some states like Illinois preclude using any rifle of this type for deer hunting.
However, we do have wild dog packs and some fairly aggressive groups of coyote.
Coyote are not pack type animals but they will group together for the chance to take down larger game.
After the kill, they disband and go their seperate ways.
For these type critters, a .30 Carbine is quite sufficient.
Again, for a person in an urban setting who does not hunt, the .30 Carbine is plenty sufficient for dealing with the roving packs of anmials one may encounter in that setting as well.
It sounds messy and unfair, but in a SHTF setting with the carbine owner low on ammo, the recourse is to shoot another and seize their weapon and ammo or fall in with a group that will provide or trade for another weapon of which sufficient ammunition stocks are available.