There is a good article in Shooting Sportsman ( Sept or Oct issue) by Vic Venters on smoking in barrels "on the circle". It illustrates the major points to consider in fitting barrels to the action. While it is certainly true that not all guns are created equal, the article shows where a little more material can be added to increase strength of the action and make it suitable for a rifle.

The same issue has an article by Steven Huges illustrating a box lock action. Another good reference for technical information is "Shotgun technicana" by McIntosh.

A 30-30 won't stress many actions, but the better it is built, the more generations get to enjoy it.