Well, Swarovski was forced to design their own version as Zeiss had 20 years long a patent on theirs. Now the Zeiss patent has expired and many companies are using it: Meopta, Leica, Zeiss and more.
The SR-rail is only used so far by Swarovski and Kahles (a Swarovski company)
and then there is /was the Schmidt&Bender Convex rail
What is the difference? From my experience as a mechanical engineer, who has developed the first Titanium made scope mount which is able to use one scope on many (Classic bolt action) guns myself and got a German "Gebrauchsmuster" on this (small patent):
The Zeiss rail: works like a wedge. The screw will pull the wedge design into the scope mount. recoil is transferred by friction only. The design is good and works normal flawless, but recoil forces are limited due to friction transfer only and the design (2parts of scope mount vs. one "bridge" design will limit it very much!)
https://www.titanium-gunworks.com/innog ... zeiss.html
The Swarovski SR rail uses recoil transfer on geometrical design. This is much stronger then the friction based transfer, but machining is more expensive due to the small teeth vs. a simple surface. Recoil forces could be much stronger and the scope won't move - until all teeth will failure. Never have seen something like that (just Blaser uses a cheap plastic insert in their scope mounts, which is the weakest part and will limit the recoil transfer especially when You don't have installed the scope mount well. The transfer of forces by geometrical design has the highest value in engineering, but it is the most expensive as well. HMS Samo and Innogun scope mounts have machined their teeth from the solid - so no week points like the original Blaser scope mount:
https://www.titanium-gunworks.com/innog ... ovski.html
https://www.titanium-gunworks.com/hms-s ... ovski.html
The S&B Convex rail is like the Zeiss rail: The recoil transfer is only made by friction, BUT their design is weak: no wedge design (which multiplies the friction forces / screw torque), and You will never have a good fitting between the scopes rail and the scope mount: one is always bigger or smaller in diameter then the other and this causes just one or small line s of contact and not a big contact surface: FAILURE - Recoil forces are weak. So that's why You always see moree screws are used then by the Zeiss rail. AND from what I heard: S&B has now switched to the Zeiss rail either - You bet why...
BUT:
I would always suggest to use a Torque Wrench for assembling - even and much more with rings vs scope rails. There is a good and reliable wrench available from Innogun as well:
https://www.titanium-gunworks.com/innom ... -6-nm.html
AND
CHECK if the screws are too long. Not seen often, but this could damage Your scope
AND
use Loctite 243 to secure the screws to prevent that they are gotten loose by time. If You want to remove them: heat the screws with a hairdryer - this will temporarily weaken the Loctite to unscrew the assembly again.
Conclusion:
Well, I would always prefer a railed scope vs the old ring mounted style as they are easier to set up, more recoil proof, You won't see any marks from mounting when You change scopes/rifles and stress free mounting. The only rail I would avoid Is the S&B Convex-rail due to its problems.
Klaus
www.titanium-gunworks.com