spit patch
How about "mouth wet" for a better term. Many on this site spit patch in-between shots especially with the 777 loose powder. The spit patch removes enough fouling and helps remove the crud ring from the 777 powder.
I have found using any of the store bought solvents leaves a slick coating in the barrel that effects accuracy. I suggest that you should double spit patch in-between the 2nd and 3rd shot. Doing so helps those 3 shot groups get smaller.
Choc-dog