I've never tried the 777 so cannot speak to that. I have noticed all the muzzleloaders I've had over the years have been more accurate with 3f black than 2f, cap or flintlock. In my 62, the 3f black is head and shoulders above Pyrodex in accuracy. I can honestly say I've never had a failure to fire with black in a caplock with either musket or #11 caps. I use musket caps simply because their easier to handle with cold hands. I have had failures with my flint but always due to a dull flint/damp frizzen or a damp priming charge. Never had trouble with the main charge if the prime was good and the flint sharp.
