Balancing shell mass, velocity, barrel life, and rate of fire

What engineering limits govern the choice between a heavier shell and a higher-velocity naval gun?

Velocity brings barrel length, wear, weight, and manufacturing penalties, so calibre, shell mass, rate of fire, and ammunition capacity must be balanced together.

Calibre and barrel length form part of a system that also includes shell mass, rate of fire, and magazine capacity. Longer barrels can droop and wear faster, while higher pressures magnify manufacturing imperfections. Heavier shells and longer guns both increase the mass that the mounting must move. Each barrel-construction method also imposes different limits on the practical relationship between length and bore. Cantilever supports introduce their own structural and thermal-expansion problems, so designers rely on careful gun engineering rather than an external brace.