It's hard to tell without actually holding the gun and trying myself but from this line it sounds like its normal...When you clean, take short strokes and work your way down to the area where the powder and bullet are...It's normal to have some buildup in this area...A crud ring is actually a few inches above the area where the bullet is.....

You might also try dropping the powder charge down to 100grs, that's plenty for deer...You could also try a little more cleaning fluid on the cleaning patch...