This is part of a 416 Rigby that's been posted over on the Campfire.

Looks like a great sight, but this post needs more detail to be of much use to anyone. At the minimum we need to know who made the sight.

Over on the Campfire site, IdahoChukar lists the designer as a Tom Delluchi, and adds that he believes that Tom has sold the design/tooling to someone else, possibly Wisners.

SBB

I've got that same sight (from Tom Delucchi) on my 400 Whelen (Mauser).

I prefer the Rigby style done by our own Rusty Marlin.
He put one on my 500 Jeffery, and after the new stock is finished I'll get Rusty to regulate the sights.

Garrett