Did you put lock-tite on the scope screws? I didn't with my last one and it got knocked off zero if you breathed on it hard. Even if the screws are tight, it can get off zero after a few shots if you didn't use lock-tite. You will be a little off too if you sighted it in when your barrel was hot, when it cools off the zero will be off to one side. Check to make sure your scope rings fit on the scope good, the scope could be rattling around in the rings.

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