For the last couple of months been fine tuning a load for 22-250, this morning went to the range with some loads with a variety of oval changes.
Switch back to round bullets and your problem may go away.
Does your rifle have a wood stock and does it touch the barrel anywhere? If so the temperature / humidity may have had an effect of the wood. What powder are you using? Some are less temperature sensitive, but I don't think 65° to 85° is enough range to make much difference.
Or you may have just had a bad day shooting...