Since I'm increasingly tech challenged, I have to post a link to the whole page rather than pirating his image. I guess that's the proper way to do it anyway. You need to scroll almost all the way to the bottom to see it. Warning--airgun site.

I'd forgotten I'd bookmarked this page. When I saw that sight I thought of its utility on an underhammer offhand rifle, but now I'm thinking of a non-folding version, elevation adjustable only (windage by drifting the front sight), and easily removable/replaceable feature to keep transport hits from damaging the sight. Sort of like schuetzen tang sights were removable.

http://www.springgunning.com/

I know adjustability is not acceptable during a match, but I like the idea of easily dialing in where you hit on your spotter, then leaving it alone. But I could be wrong as well as ignorant.