This past benchrest season I've shot 2 5# jugs and 3 1#'s. I shoot this in a cartridge that is 3/4 grain less than a regular PPC.
It has shoot very well and I have not found that I had to change powder settings. I shoot 27.9g behind a 67g AA bullet and get about 3330 fps.
It does show up dirty to the borescope but just a regular cleaning regimen keeps the gun shooting in tune. The light streaks of powder fouling don't seem to have any effect on performance. Matter of fact the barrel has to be foued slightly to shoot well.
When 10X first came out we were in Painted Post shooting the iBS nationals. I had bought 3 cases of it and at that shoot sold 2 of the cases. The guy I sold it to still shoots some of that original lot.
The 6PPC is probably slightly too big for 10x just as it is slightly too big for V133.