How big of a target were you using?
I put up a thread a few months ago, right around the opening of the spring season on exactly how I go about patterning a turkey gun. Here is a link directly to the thread.
http://www.huntingnet.com/forum/tm.aspx?m=2074825&mpage=1&key=pattern& #2074825
As to fixing your point of aim problem, you need to either get your gun shimed to correct your cast problem (if you are right handed and shooting right, you will need a degree or two of cast off I believe), or you will need some sort of sights/scope. I use a scope on my turkey gun, and its a great tool.
Good luck.