Start moving your targets out to 1,000yd intervals.
Make a drop/wind chart.
It's already a thousand yard shooter if you do your part.
What scope have you got on it?
The interlock is a great performing bullet. For target shooting you might want to consider the Bergers or Lapua Scenars though.
The Scirocco II is also a great hunting bullett and the 180gr has a .520 BC. They shoot great for me in my 300 Rum and 300WM.
They'd be worth a look as well.
The Nosler Accubond 200gr may well be the best all around LR hunting bullett for the .30 Cal so try it as well while you are experimenting.