Some great information on this thread. I've just recently purchased a Hornady concentricity gauge and I checked the handloaded ammo I had on hand for five different chamberings. All needed some tweaking to get the runout at or under 0.002" but the worst offender was my .280 Ackley. I'm amazed it has shot as well as it has with the runout I found on these rounds. Hopefully it will group even better with straight ammo.
You need to start with your die set and make sure it is adjusted properly. You can minimize run out tremendously by just adjusting the die... This is probably the case with that .280 AI...
