Aussie article pointed me at this, Verney Carron has a Speedline rifle and a Veloce shotgun out, a lever operated semi-semi-auto action. Says it can fire 6 shots in 3 seconds. They are definitely thinking out of the box on this.
The patented « Stop&Go® » system allows an
unequalled rate of fire on a manual repeating
shotgun by locking the bolt to the rear after
automatic ejection of the fired shells. The reloading is
achieved by a light pressure on the lever.
https://www.verney-carron.com/pdf/ca...ney-Carron.pdf
https://www.youtube.com/watch?v=p7eYuI739Tw
https://www.youtube.com/watch?v=eQ5a9nEYFWo