Why don’t modern shotguns have a dolls head?

Shooting technical advice
MIKE GEORGE
The dolls head extension supplemented the strength of the bolt and the jointing to resist firing pressures.

It consisted of a rearward extension of the top rib with a disc-shaped end which dropped into a circular depression in the standing breech.

The alloy steels used to make up the barrels, actions and jointing of modern shotguns are superior in strength to those of old, which is why the dolls head has been relegated to history.