Greenboy shells and the Battle of Jutland

With Greenboy armour-piercing shells available at Jutland, the Queen Elizabeth-class battleships are expected to inflict far greater damage on the High Seas Fleet during the Run to the North. Postwar firing trials against Baden and Bayern provide the basis for that counterfactual. The 15-inch/42 shells performed roughly 10 to 15 percent better than commonly used armour-penetration formulas predicted, possibly more. Calculated performance therefore needs comparison with firing results. Conservative engineering estimates and optimistic sales claims can also give quite different impressions of the same weapon.