A month ago I took my rifle (Weatherby Vanguard S2 in .308 with Redfield Revolution 2-7 scope) to the range to confirm zero and see which brand of ammo it liked best. At the end of the session it was right on target and shooting tight groups with several different brands and weights of ammo. It liked CoreLokt 180 grain ammo best and shot sub MOA groups with it. As always, upon returning home I thoroughly cleaned the rifle.
Today I went to the range to practice for deer season, and to my surprise my rifle was shooting around six inches to the right of the bullseye at 100 yards. There was a good wind, but it was blowing to my six, not across the range. I check my scope mount screws and action screws, but they were fine. The rifle consistently shot six inches right multiple times with a couple different types of ammo. I adjusted my zero, got back on target and shot good groups.
Any thoughts on what caused this? I have never had trouble with this scope before and it did not see any hard treatment between trips to the range. I am worried that after flying to PA for deer season it will be off again, and I probably will not get a chance to check my zero before hunting.
Thanks in advance for your advice.