I looked at the Sav99 rotor and gave up on getting 6mmBR to feed.

The $175 1917 take down 250 Sav has an extra barrel now in 6mmBR.
The original skinny barrel fits with the fore end, but the bull barrel does not. The original barrel is shot out and coroded. I may buy a skinny barrel blank and mill a dovetail cut in it to fit the fore end.

I bought another Sav99 to rebarrel, a Sav99C 308 with detachable magazine for $350.
This rifle has a like new bore, but the bore was of poor quality originally from the factory.
I prefer to work with stress relieved and factory lapped barrels.

The mill work on the breech of a barrel blank to get it to fit on a Sav99 is elaborate. Real gunsmiths may be able to do it quickly, but each cut takes me hours.