There is no hard and fast rules for break in, just use common sense. Make sure the barrel is clean, she may leave the manufacture with oil in the barrel, so run a dry patch through her. Use a good oil and generously oil all the moving parts. Make sure the barrel retaining nut is tight. I would suggest you put a box of 2 2/3 inch through first, a light load and then use any 2 2/3 load for the next 200 rds, slug is fine. Then feel free to move up to three inch loads. Remember to put a couple of drops of oil on the thread of the choke screw her in snug, do not over tighten. I do not recommend firing slug through the full choke.
We do have some extra chokes in stock and will be running accuracy tests with a rifled slug choke. Watch for results.
We will post photos of the shotgun as soon as we recieve them. Right now only have have reached Winnipeg, thanks Air Canada, so we have lost another day.