Shell guns do not save the Hanseatic League

What if the Hanseatic League developed shell guns in the 1600s, and would the new weapons unite it?

Reliable shell guns could make Hanseatic ships more intimidating, but would not remove the political pressures behind the League's decline or turn its trading confederation into a unified state.

Seventeenth-century metallurgy would make shell guns dangerous to their own crews, with uncertainty over whether the weapon would burst aboard the firing ship. Mounting the guns on the upper deck could keep an explosion outside the hull, but protective brickwork would add troublesome topweight. Metal lining is suggested as an alternative, and catapults carrying incendiaries as a less ambitious option. Even if the question grants reliable shell guns, the Hanseatic League remains a trading confederation that arms ships to protect commerce. More intimidating ships would not remove the political centralization in Germany identified as the cause of its decline.