I never saw a Krieghoff insert for a major big centerfire caliber like 9.3.
What I have seen from Krieghoff is a smallbore insert in .22 LR, .22 WMR, or .22 Hornet made to go in one shot barrel of a drilling. They have adjustment screws so you can set them to shoot to the sights of the main rifle barrel in the drilling. The rimfires are offset for the regular firing pin, the Hornet is centered up.
Here is one of the type:
I'd be interested to know about something higher powered. A 9.3x74 is a lot of load to put on a plain shotgun action meant for about 1/4 the pressure.
ETA: I looked on the Kreighoff site and found mention of the KS full length insert in calibers up to 9.3 all right. But it says:
"NOTE: KS Insert Barrels are available from Krieghoff Intl only factory fit to new Optima Drillings."
The drilling is built strong enough for rifle loads so a full power insert is feasible.
The old style smallbore inserts were only 12-16" long, good enough for the small game application.