No. The only thing that has happened this past week is the air drying out. The monsoon season is going away.
I will be going back to the range Friday to see if there is another shift.
I did not shoot the rifle very fast and heat should not be a major issue.
I do wonder if the windage adjustment might have hung up. The scope has really been trouble free and has seen service on my M1A.
The thing is, the elevation was still spot on. Only the windage had changed.
Had it only been a small amount, it would not be an issue, but 4 inches is a LOT.
Even different lots of ammo would most likely have changed elevation. . .not windage.
There was no wind to speak of either day.
If there is another shift, I will readjust scope and tap the turret to reduce backlash and reconfirm zero.
I do not know how tight the bedding screws should be but they were not loose and moderate pressure did not move them.
One thing I can do, now that I think of it, is to put the laser bore sighter in the gun and deliberately turn in a bunch of windage and then take it back to zero without going past zero. Then tap the turret and see if there is a change.
It may be the adjustment needs to be made in one direction only.
I know from past experience with musical instruments, you never adjust a string down to pitch and leave it. You ALWAYS tune below and bring the string up to pitch and tension the adjustments with the load in the same direction.
I will see what happens come Friday.