Since you have an Omega.. have you tried shooting Shockwaves? The 200, 250, even the 300 grain should shoot very well from your rifle. Now granted, some Omega shooters claim they are hard to load. All you can do is try them. They should give you excellent accuracy and killing potential. Some Omega shooters even push them to 150 grains with pellets. I personally would not do that, even 120 grains would be plenty.

Normally when someone is having trouble with a rifle, a wise man told me to stick with combination bullet sabot loads like Shockwaves, T/C Mag Express XTP's, T/C PTX, etc. I've done this and always been able to find one projectile or more that gave me excellent results.

Then again, maybe you were just having a bad day. I sure get enough of them... Better luck at the range next time.