TargetTalk

It worked! Gentle heat has released the ring and it now has the full range of movement. If you need any advice about muzzle loading Match Rifle shooting that is my speciality; not using magnifying diopters with them though. Thanks again.

Many thanks, I will give that a try.

Thanks Tim, So I should secure it tightly in the backsight then rotate the double knurled section to refocus? Sorry to keep coming back but it does all seem to be very reluctant to move.

Thanks but I can't find anything that turns other than the adjustable iris. There is the thread that goes into the main body of the sight then a double knurled section with the words CENTRA UK -3.5/+3.5, this seems solid with the rest of the diopter then there is the adjustable iris that seems to wo...

Does anyone know how to adjust the focus on a Centra 1.5x magnifying diopter? I can't find any instructions on the web. Many thanks.