I personally do not shoot an Omega but I am starting to think that if you're going to use pellets then you can use 100, 120, or 150 grain with different projectiles and still get excellent accuracy. Especially since you want to be able to shoot out to 200 yards. Look at the 200 or 250 grain Shockwaves and try some of the different pellet combinations.

If you're going to shoot loose powder then I would not shoot over 120 grain of the loose powder. I would also use the same projectiles. That is a great rifle you have. With practice you might be able to shoot to the distances you want.... Also, I have no experience with the Hornady Lock and Load Sabots.

I shoot a Black Diamond XR and get excellent accuracy out of it. It has the same kind ofbarrel as your rifle, just a different action so I have been told.