Looks like you're getting good patterns out of that barrel. You're going to be hooked!
Have you got a .690 RB mould? That will be next.
I find my NE barrel likes loads with just card wads between the powder & shot. I cutwads out of old shoe boxes & milk cartons and load 2 over the powder & 1 over the shot.
Fun to play around with loads in it, and it's a lot easier to clean than a rifled barrel.