RE: 777 vs. Pyrodex (pellets)
Since I started using american pioneer powder,I won't even THINK of using anything else. We had 3 knight rifles all equipped almost as exactly same as we could and tested different powders side by side. This includes chronograph,accuracy,among other testsas well asease of cleaning.
After 2 days of shooting and trying every combo we could come up with,we came to some interesting conclusions. #1-loose powder seems more uniform than pellets of any kind. #2-actual black powder is most uniform of all but don't seem worth the extra effort of combatting corrosion. #3-of the black powder substitutes,american pioneer powder burns cleanest with NO buildup,excellent accuracy,and is easiest to clean.
I did find out that with a magnum 209 primer,90-120 grains of FFF american pioneer powder seems to be the load by which we judged all others depending on bullet choice of course. I could go on but am likely boring yall.