I would evaluate your seating pressure.

Are you seating your bullet to a specific mark on your ramrod?

Doesn't really matter how much compression on the load, light, medium, or heavy....as long as each shot is seated withthe same exactamount.

Use masking tape to mark the rod andfind your best seating pressure, then make a permenant mark for future use.

Also, I've seen this sort of thing with volume measured charges, to eliminate that variable I've weighed charges for a long time now.

It could be lots of other things but I'd make sure those issues are looked at first.......no reason for an Omega to shoot flyerslike that if all things are good to go.

As an aside, I've always got 240 XTP's to fly best with Hornady green sabots and T/C Black's..........