I had a look in
Naval Weapons and they don't have penetration charts at all, so the info has to have come from one of the cruiser books, and I don't have either one.
So-called common shells have come in a great variety over the years, and with many different names. The British have called them Semi-Armour Piercing and SAP Common, but my favorite of theirs was SAPCBC (Semi-Armor Piercing Capped British Common). According to
Fletcher Class Destroyers (don't remember the author as I looked through it in a library), United States HC (High Capacity) was meant for shore bombardment and designed to penetrate up to 10 inches of concrete! How effective that was on a ship's armor I don't know.
I'm just always leery of giving any kind of Armor Piercing capability to any submarine gun since the smallest ships to regularly carry belt armor were light cruisers, and you shouldn't oughta be taking those on with a deck gun!