DoeDumper...Another point...The jags for most traditional rifles are too big (diameter)...They push thefouling down the barrel as you mentioned...Chuck it up in a drill and file it to a smaller diameter, this way the damp patch rides over the fouling on the way down and pulls it up and out on the way up...

Also, I noticed in your other post you were using 85-90 grains of powder...With most button rifled 1-48 twists rifles you will do better if you drop the powder charge as mentioned, what most folks don't realize is that real black powder, leaves about 57% residue...So by reducing the charge, you also reduce fouling...So especially when target shooting and small game hunting, its fine to take the load down to 40-50 grains in a .50 caliber....