You are going to have to shoot some to see what your rifle likes. I am one of the guys that has not figured out how to make Tripple Seven work in my Omega. I have a real time with the crud ring which simple spit patch swabs will not remove. Wet patches and wire brushes are required in my rifle. I got real good results with both loose and pellet Pyrodex and the fouling is heavy but soft. I get real good results with the ascorbic acid based powders like Black Mag'3 which is my personal favorite but it is difficult to find and expensive when you do find it. I have some Goex Pinnacle which I have not shot enough to comment on yet and American Pioneer shoots well for me in the fffg form. These powders will leave very little fouling and multiple shots without a swab between are possible. Where you are; if it were me just starting with the Omega I would probably use Pyrodex and after developing some confidence in the rifle try some of the others. Tripple Seven makes high initial pressure and in short barrel rifles shoots very good. In my Omega I did not get the high velocity that the heavy recoil experienced with 777makes you think you should get; all I got was a bad crud ring and a heavy sharp recoil. Accuracy is not a factor in the Omega as almost everything I have shot will give you decent accuracy. The rifle is very accurate with almost anything from 200gr. to 400gr. bullets. I do not shoot maximum loads and usually hunt with 100gr. powder loads or even some at 90gr. (expecially with Black Mag'3).