RE: 777 use in Omega?
A lot of us Omega shooters find the MMp HPH 24 an excellant match with 120 or 130 gr powder and a 451 or 452 bullet Shock Wave XTP and Speer gold dot in the 250 gr all shoot an inch group in mine.
As for the powder Black or Pyrodex has work in all most all black Mag if you can get itsome have good luck with 777 I have not gotten past the "crudring" myself but have had good luck with APP ff except for a bad can.
Lee