I have a waterfowl edition. I've never done anything to break it in per say. A buddy and I went to a sand pit and just tried a bunch of stuff to see how it cycled. I've never had a problem with any load. I'm not sure if the longer barrel on the waterfowl edition had any influence in that or not.
The biggest thing for me was making sure the gun was clean. They use some heavy grease from the factory and it had a negative effect on mine, most noticeable in cold, sub freezing, temps.