Nitrox

This is a Docter sight from Germany. Here is the link to the manufacterer in the US: http://www.docteropticsusa.com/doctersight/index.html

Can recommend it. Nowadays some kind of standard equipment on double rifles here in Austria and Germany.
Get the 3.5MOA version for the rifles.

Battery lasts for years (mine is working for 2years now - still bright - for a safari put in a new battery and let it glow 24x7).

I have one on my 9,3x74r Tikka double and one for my CZ550 416 Rigby (as 3rd backup) - just get the standard mount for the 14mm rails (? please measure) and put it on the standard rail on the Tikka - 2 minutes affair - insert battery - mount sight on mounts - put on rifle.

There are different bases available which can be used with a single Docter sight for several rifle models (but you have to sight in the Docter sight when you change from one rifle to the other).

This makes a VERY small and light backup scope to be carried in your pockets all day (sizes like two boxes of matches put together) no matter where you go.

Can be used to 100yards on medium sized games without problems - shot my Tikka with 2-3" on 100meters.

There is a pin on the bottom of the 14mm mount - put it into the hole in the rail resting to the side of the muzzle.

Works great - make sure where the barrels hit at - might surprise you how low the Under barrels hit between 0-50 yards.

For a SxS it sure helps getting on target and with so little weight shouldn't affect regulation at all.

Cheers,

Franz