Minus the often talked about alleged gun use on the Titanic, understanding the weapon used that night is historic and lengthy. The Mark IV used the night Titanic sank is one of many designs in this weapon's profile. From what I understand this weapon was successful for the conditions it was used for. Refining the design is understandable. But, a weapons company, such as the one who created this weapon, often will tinker to the point that the original design becomes dated and often dropped from production. Progress is one thing, but dumping a tried and true design is something I don't understand.