Shot a new 280ai today with 175 Elite Hunter and RL23. Used Peterson brass which I think may have slightly less volume capacity than Nosler brass. Was 92 degrees. Speed at .6gr off of Berger provided max load was 80fps higher than their max load velocity. No pressure signs other than a very faint extractor print. I kept the loaded rounds in the air conditioning until ready to shoot. This is the second outing for this rifle. First outing was with RL 26 and I hit pressure signs below the Berger provided max. Did not get speed on the RL26 loads. So hot temps or Peterson brass explains higher velocity? Or both?