US Projectile, 3 inch HE, Mk 9
The Projectile, Mk IX is of steel construction, and is shorter and lighter in weight than the Mk I. It has a radius of ogive of 7 calibers, and it continues its cylindrical shape from the rotating band to the base. The rotating band is 1 inch wide. The filler is 0.91 pound of TNT. This shell has a steel base plate and an adapter.