Don't get me wrong...Ruger made a nice revolver--about the size of a L-frame S&W, not the N-frame! Not enough room in the chambers to launch that ball fast enough to give you anywhere near the power factor of a .44 Spl! My .44 spl. rounds are factory Magtech 240 grainers. They go out of a 4" test barrel at 761 FPS, so add another 30-50 FPS when shot out of my 8 3/8" Dirty Harry S&W Model 29! That's a power factor (speed X weight) of about 180 or so. Those cowboy loads make IPSC Major classification!
Smaller, lighter round balls may travel faster, but they don't have the mass.
As for 777, since it says not to compress it right on the label, it will never go in my guns, cause out of habit I compress black powder in black powder guns