I am waiting for mine to be delivered. I have shot my O & U and found the sights to be lacking, making any regulation nearly impossible. I mounted a scope on it tonight.
If the SxS has that AK-47 style post front sight, then a scope is the only way to go.
What grain bullets were you using? Did the barrels hit together? It sounds more like a sighting in problem, unless of course you are talking about where one barrel is hitting compared to the other.
George