That's a reasonable load. You may be cutting patches when loading through a sharp crown. Try polishing the crown with 800 grit sandpaper & your thumb. Cut a small square of sandpaper & place it under your thumb on the muzzle. Rotate the barrel 10 or so times, then reverse the rotation for the same number of rotations. Repeat until you get a nice, smooth, crown without sharp edges. Failing that, you can polish the bore with green Scotch rite pad. Just put a piece of pad on an undersized cleaning jag pull it up & the bore until the pad gets worn & then switch pads. Repeat 2 or 3 times. This is a method championed by the late,, great, Don Goetz.. You are not likely to hurt the barrel with either method. I'll bet that the crown polishing will suffice.
Roger B.