Working up a load today and had something interesting happen. Wondering if what I saw is consistent with what you all have seen. Shooting .5 grains at a time to find max pressure with RL26 and 140 Bergers in my 6.5x284 and looking for flat spots in velocity along the way. Shot sighters at Target #1, one of each charge at .5 increments from 53.5 to 56.5 grains. As you can see, all shot fairly close with the exception of the last one, went high and left. Figured it was just dead on a scatter node or I pulled it. Moved on to shooting 3 shot groups around some of the flat spots I found during pressure test. This is where the head scratching started. Groups 2 through 5 all shot 2 together and then spit one way out and they followed the POI of the "flyer" during the pressure test. Kept adjusting my hold and could not figure out why in the heck the group POI was so far out of the pressure test POI and why in the heck the flyers were so bad. Right after group 5 was shot, I was literally scratching my head and looked down at my brake, it was loose by about 1/8 turn. Tightened it up again and had one more group to shoot, not a great group, but the POI shifted back to a reasonable location and the flyers went away. It must have cone loose on that last sighter on target #1. I can see the loose brake causing a POI shift, but I am still dumbfounded about how it woild shoot 2 together and then spit 1 way out. Ever see this? I am pretty tempted to shoot a seating depth test with 55.5 grains or so, but maybe I should scrap the whole test knowing what I do now.