Try conical's in your Omega with a wad on top of the powder.

The 1:28" rifling in the Omega should toss conical's just fine.

Add your charge, load the wad, then load the conical.

Also, even though the Omega has a false muzzle (QLA) which does make loading easier it still takes some practice to get the conical "engaged" or cut into the rifling. You need to give them a short "smack" with a short starter. If this is not done consistantly, your grouping will not be there.

I've not shot the NE conicals yet, but have hornady Great Plains and Maxi-Hunters in hefty sizes with excellent results. Takes some practice to get the hang of loading conical's correctly.

Lastly, bench shooting from a stable bench should help with accuracy as well.