Question what is the relationship between Pressure, FPS, and seating depth? Does more seating depth create more pressure or vice versa? Does seating depth have a direct impact on FPS? Here is my issue: The rifle I am shooting 6.5x284. 140 vld. 24" barrel. 56.5 grains retumbo. .100 off lands. Lapau brass. Fed 210M primer. There is another thread regarding this chambering that had got me to thinking, I know I know, I should not think..... but hey too late. Thinking about whether I could load to the lands and have enough bullet in the case neck for proper tension and alignment. I wanted to test and see if I could do this and gain accuracy. I tested some loads where the bullet was seated to the lands, in fact, .003 in the lands. I tested a 3 shot group and they all flew in the 2970 range. I am seeing faint extractor marks. Accuracy was OK, .75 at 100, the wind was horrible, gusting from every direction up to 16 mph. It blew my chrono over, the target over about 5 times, it was a pain to say the least. I shot my normal load that is .100 off the lands, 2900, which I expected. I am still seeing some extractor marks, little stronger, with 56.5. Hmmm, so I load up another group and pulled them back a little, 002 off the lands, and they flew 2950. Still pressure signs, but faint. OK, so I am baffled. I load up another 3, .002 from the lands and change from 210m to 215m and I am getting 2980 to 3000. .75 MOA in the crappy wind. Load up another 2, the last I had to test in the field, and pulled back to 56 grains, .003 into the lands, and a solid 3000 shows up on the chrono and .30 group. I wish I had a 3rd to at least get one more on paper, but I saw what I needed to at least do another field test, no pressure signs.