A well tool has an inner and outer component arranged to move relative to one another and defining a shear juncture therebetween. A shear member spans the shear juncture. The shear member has first portion with a different cross-sectional area than a second portion. A cam surface is associated with the inner or outer component and abuts the shear member. The cam surface moves the shear member as the inner and outer components move relative to one another and changes the shear member from having the first portion aligned with the shear juncture to having the second portion aligned with the shear juncture.