I agree with the first post regarding the load. I use 110 of 777 and a 405 powerbelt. My bull dropped right where he was shot. I also shoot the omega. I would suggest starting at 90 and testing groups from 90 to 115 of 777 and see what your particular gun likes. I was able to get a 2.5" group at 75 yards with open sights. Frankly 80 yards or so is my limit with iron sights even though I know the gun can shoot much further. I would also much prefer a heavy bullet with a moderate load than a light weight bullet with a higher load.
Cheers
Roadtrip
"Fat, drunk and stupid is no way to go through life son" Dean Wormer, Animal House