Originally Posted by tugg
I've had a Bushnell scope that just naturally made you have to aim off on close ones, don't know why could of been not centred or cross over even when making absolutely sure your eye position was correct it would shoot left
That'll be parallax error again.
Unless your scope is optically centred, having your eye lined up with the centre of the scope is the wrong place to be, it's only the right place to be when you're optically centred. I only realised that myself a couple of years ago, but it makes sense when you think about it.