I put a fibre optic bead front sight on my CZ550 in 416 Rigby. I put on a taller one so I could use their Peep sight. This necessitated me using the 200 mt express sight to be on at 100. Works well as it is spot on at that range. Where the author has hit the nail on the head is the damn thing can fold down with very little encouragement. So I have glued this leaf in the up position. Problem solved.