ORIGINAL: jaybe
You may get various opinions, but in my experience:
1. 777 is MUCH cleaner burning and easier to clean up.
2. 777 CAN cause a "crud ring", a buildup of harder, crusty-feeling fouling at the point where the bullet was seated on the powder. This can be easily removed by swabbing between shots (which many do anyway), but it can make reloading a second shot in the field tougher. I believe this is made less a problem if a cooler primer is used - regardless of which kind of ignition is used. In my White Ultra Mag, it is not a problem at all.
3. 777 is approx. 15% hotter than Pyrodex. In other words, a load of 85 gr. 777 is roughly equivalent to 100 gr. Pyrodex. You will get more shots per pound with 777, if you dropped down 10-15% on your load volume.
4. Some guys say 777 has a "sharper" recoil than Pyrodex. I can't tell the difference.
There's probably more, but those are the differences I am aware of (that I can remember).
Good Luck!
what you said about the cooler primer got my attention.
i have all ways used a standered primer and like you said theres that crud ring to deal with.and like you said i swab between shots just to keep it consistent, so i just dealt with it.
then i found a primer that Remington offers made for muzzeloading .
and now i did not have the issues that i normally have loading ,there is still something there like a crud ring but ya can easily push past it.and the primer is a hard primer so theres no way that an encore firing pin will get stuck in it(ya been there done that)