Burntmuch
Nice Rifle
Be sure to compress the load/powder
VERY Firmly each time with JSG/Any APP brand of powder. It will give you better accuracy results. In fact you can give it all you got, compress it in a slow even push, till full compression(no more movement is felt).
Do Not bounce the Ram Rod Don't worry about the shockwaves or XTP's, they can take the loading pressure with out distorting the bullet
You can deffinatly start at 100g powder and move up or down from there. I've used 150 loose JSG 3Fg in my 45cal Disc Elite, but don't like the recoil
I've settled for 120g powder max, and get excellent groups at 100 yards.
With just a 24inch barrel on your omega, I would say 120g JSG would be your max burn limit anyway.
You are gonna have a great time
Keep us posted on your range results