If I had an Omega and it was legal where I hunted, I would be shooting a 200 grain Shockwave. Powerbelts are too expensive, and I would rather let the rifle do what it was designed to do.. shoot a projectile at high speeds in a flatter trajectory.

If the shooting was close quarter stuff, I might also consider a 200 grain XTP and again, shoot them. Although if you are getting good accuracy with your powerbelts, and like the ease of loading, then lower the powder charge a little and you should be fine.