Buckshot Patterns

Last weekend found me at a friends ranch. Much shooting was accomplished, to include patterning buckshot loads for my home defense 870. Here is the winning load:

Federal low recoil, 2 3/4, 9 pellet, 00 buck.

I am very impressed with this Federal load. I did not pattern at 25, but I am positive that it will stay on a silhouette target.

Something seems to be off on my shotgun. I adjusted the sights on my shotgun, they seem to be off to the left. I don't think it's the load as both the slugs and the buck seem to be off the same amount. I took off the barrel and reseated it, same point of impact. Slightly odd, but it hits to the sights.