Yes to all the above and more. Get rid of 777 and go to another powder. I don't care which one, but I ended up using BH209 for my inline guns. For mycaplock and flintlock guns I use the real deal (BP).

Now as to the BH209. You must have a closed breach plug for this powder. I shoot a Knight Vision and NEF Sidekick with an upgraded bp and it works wonderfully. I have shot this powder at the range for 25 continuous shots without cleaning the barrel. I only stopped and ran a wet patch and dry patch to see what was in the barrel. It was hardly dirty. I also pulled the BP and found a light dusting of carbon dust and no hard carbon on the bp face. This impressed me quit a bit and I now use it faithfully. Oh yeah, it along with my bullet combos hard tack drivers. I am using a 300 gr. XTP sabot in the Sidekick and Harnady 350 gr. FPB in the Vision.

Hope this info helps pal. Good shooting.