http://www.seeallopensight.com
saw a guy shooting a rifle with this sight today. He let me try it and I hit 4 for 4 it seems to be a good concept might work good on a double rifle

Interesting concept. I have not been able to use open sights in a while, "old man" eye sight thing! For hand guns I use a micro red dot sight. Burris and Leupold are a couple that make em. Tough as nails. 3.5 MOA is good enough at 100 yrds. Fast and compace. If I ever own a DR thats what I would use.

Looks like they are still fairly new. They appear to be mechanically simple and don't need batteries. That should make for a reliable sight.

I wouldn't mind giving one a try.

Really interesting concept - I see no reason why it would not work well on a double rifle. I hope somebody here tires one and posts field test results.

My question would be, how will it hold up under the recoil stress of a hard kicking big bore?

465H&H

Recoil is one issue. A second is whether your head will be too high. Not good for accuracy and not good with a thumper.