A Royal Navy 15-inch/50 upgrade program

What weight and operational difference would adopting the 15-inch/50 make in Royal Navy twin turrets?

The gun was only modestly heavier, but turret conversion would be substantial; an early rolling replacement program could nevertheless give much of the battle fleet a major upgrade.

The gun itself is described as not dramatically heavier than the 15-inch/42, but installing it across existing capital ships would require extensive turret machinery and balancing work. A proposed rolling program would put newly built turrets in the first ship and modify its removed turrets for the next. Retaining the Greenboy shell lineage and standardizing much of the battle fleet on a stronger 15-inch weapon could also alter British gunnery development before the Second World War. The timing is decisive: a fleet-wide program begun in the 1920s remains plausible, whereas the same reconstruction becomes prohibitively expensive after about 1929.