Originally Posted by George

A barrel can't be phisically changed once it leaves the manufacturer, @ least not without a trip to a machine shop. There are a whole series of rounds based on the 30/06- the 220 Swift, 280 Remington, 8mm/06, 35 Remington, probably a couple I can't think of @ the moment. If you had a rifle with a quickly changed out barrel, the base camp could possibly have barrels in any or all possible 30-06 based rounds. In theory the camp could make a decision about witch round would be optimal for the days mission, but this is probasbly beyond financial feasibility except in limited situations. We are still where an individual wouldn't carry 2 diffrent rounds or non interchangeable magazines(same mag would work for all 30-06 based rounds).