5shot when you mean clean well are you refering to a complete tear down (meaning barrel/action/stock removal)? I know in my case after doing a tear down clean I have a slight POI shift that requires adjustment. However regular cleaning - bore, breech, nipple, bolt assembly, etc I don't have any shift or adjustments required.

I assume it is scoped? If so and your finding after regular cleaning/storage you require adjustment I would look at your scope as potential cause. First I would ensure the bases and rings are snuck and no scope slip is happening. If that is fine the scope itself may not be holding zero. If the load is the same and no global changes their is no way you should have to re-adjust a scope to obtain zero. Even if you left excess oil (a dangerous practice due to increased pressure) it would return to normal without adjustment, same would be true with a bore that liked some fouling. If this is the case I would be sending the scope back in the off season for some warranty work.