Always Aiming To Be Number One!
With higher magnification comes greater exaggeration of parallax error. Therefore it makes sense to get a scope with adjustable parallax (for most uses) that you can set for whatever distance you're shooting at, regardless of the type of rifle used.
With the parallax adjustment on the objective lens these are the cheaper option offering an effective way of eliminating parallax error.
The side parallax adjustment, also known as side focus (SF) is generally deemed the better system to use and much easier to adjust 'on the go'