If you had shot the 61.5 at 90F and had the same results, I would've shot a few more groups to verify and then called it very good...
In the 270 with a 150 grain bullet and reloader 26 John Barness, "AKA Mule Deer" noted that as temperature increases velocity decreased by a small margin with reloader 26 and also in some other powders though he didn't mention which ones.
Trystan
