Hi Mossberg 4x4 270 owner..
You have run into the problem of a bad scope. I would bet that this came with the Rifle as package. These packages add a scope for almost nothing because that is what they are worth, nothing. If you can pull together about 150 dollars you will be able to buy one that will last a lifetime. I really like the Redfield Revolutions, or the Nikons. There are better scopes available then these but you will get 90% of the quality for 33% of the price.