Hi Daz

Not wrong exactly; you've just wound the front ring out too far. Wind it back in.

I re-parallax like this.

Set out a target at your chosen zero. A simple crosshair "+" works well.

Adjust the reticle so that it's crisp and clear.

This next bit is usually easier with the scope removed from the rifle, and using a beanbag.

Wind the front ring out A BIT AT A TIME until the target is in focus. Now move your head about a bit [but
without moving the scope, of course] and adjust the front ring a bit at a time until the reticle stays
stationary over the +. You have now removed parallax error at that range.

Butler Creeks or whatever to lock, and job done!

HTH h j