I have pulled bullets in a load that was not thought to be compressed and found the powder clumped as yours. I decided it was a bullet seated deeper than the book or the powder not settled properly, and resulted in a slightly compressed load. That said compressed loads work every day. Your powder seems to have none of the symptoms listed as signs of degraded powder. I see no flaw in your reloading at all. In testing I believe that CCIs shoot tighter than the others in many of my loads, I have had 3 fail over the many years I have been using them. One in my 6.5-284 that looked similar to this. The primer fired, black color in cup but failed to ignite the powder. Could this be just a weak primer that had a too small amount of compound to work properly? I cannot tell from the picture if this is a small primer or not, but read years ago on BRC that a small primer was on the edge of being too weak for 40 grains or more powder. If these are small rifle primers, maybe try some small rifle magnums and see if it helps. Good luck!!