In this case:
"When I shoot the #1 buck at 30-40 yards it throws the buckshot in the outer perimeter of the target(full chokes), maybe one or two pellets are seen 6-8 in. of the center."
You are describing a classic "doughnut" pattern that results from too much choke for the specific load. Inexpensive single shot fixed choke shotguns have an outside swaged taper choke that does vary from gun to gun. Since you cannot change chokes, you will have to fit the load to your choke. That is try several different loads until you find one that patterns to your satisfaction.
Since you like #1B, you may want to try the 2.75" 16 pellet load from Winchester. Lighter weight buckshot loads tend to respond better to short funnel type choke constriction.
The both lengths of 12 gauge #1B loads are the only hunting buckshot in the Winchester line that are both buffered and loaded in a protective shot cup.