I would pattern it at the type of shooting you are going to do. If it's for hunting than I would patern it for 20 yards, 25 yds, and 30 yds being the farthest. I wouldn't attempt any shots farther than 35 yds.
If used mainly for skeet I would pattern it at 20 yards on a 30" circle a few times with different size shot and see which gives the best pattern and percentage of shot in said circle.
I've owned a Rem 11-48 .410 25" imp. cyl. barrel since 1967 that I bought in the rod and gun club in Germany and have used it there for hares (10 lbs) hungarian partridge, ducks (mallards, teal) and pheasant. Was using 3" Belgium waxed paper shells that I had to scrape the wax off in order for them to cycle. Have not fired many 2 1/2" 1/2 oz. loads in it, but I would like to try it for skeet with them.
