Sub-calibre
Naval
When projectiles are smaller than the bore of the gun they are called sub-calibre projectiles, and are fired from the guns by the aid of contrivances which reduce the diameter of the bore to the size of the projectile.
When projectiles are smaller than the bore of the gun they are called sub-calibre projectiles, and are fired from the guns by the aid of contrivances which reduce the diameter of the bore to the size of the projectile.