Josmund

I would venture to guess the CR is to loose for BH and the bore of your Knight. I use the MMP HPH-24 in all of my Knight 50's and they really load with I feel is the correct pressure. You might also try the longer regular Black harvester with the 300 grain bullet. It may give you a larger bearing surface on the orgive of the longer 300 grain and offer more contact with the lands and grooves of the bore...