It is absolutely common with ANY package rifle. There is almost always oil under the rings and bases, and most importantly, in the mounting screw threads. Factory mounted scopes are rarely mounted square and true.
My Mossberg MVP came out of the box with a Weaver mount on the receiver. Even under virtually non-existent 5.56mm recoil, it quickly worked loose. The screws weren't tight and there was oil under the base and in the threads. Took it all apart, de-greased everything with brake cleaner, applied purple loctite to the mounting screws, torqued them down, re-mounted scope. Problem solved.
A friend of mine recently purchased a Rem 700 package rifle. Scope and mounts worked loose during barrel break-in. He also found the scope wasn't mounted squarely. Fix was the same as above.
Moral of the story: NEVER trust factory or store mounted scopes and mounts. ALWAYS remove, clean, degrease, mount and torque rings and mounts yourself. That is the ONLY way to ensure everything is mounted properly and securely.