Originally posted by MANDOBLE
These guns would be excelent anti-ship weapons, a good choice against destroyers or, if included in the future, cargo vessels.
Well, in real life they wouldn't be. While the B25H was designed to use its 75 mm versus shipping, it was costal shipping and anti-submarine patrols one had in mind for the gun. A destroyer is far to sturdy a ship to take much damage from a couple 15 lbs rounds.
Even your standard merchant ship could withstand a great deal of damage, especially the larger ones, altough this varied according to cargo (crude loaded tankers were rather vulnerable, for example).
That's why destroyers moved to greater calibers after 1905. Up untill then 75mm would suffice, as the destroyers of the time were about half as large as the later models (also, their primary function was to engage torpedo boats, and rate of fire was essential for that purpose). To be sure, it took a couple of hundred rounds to disable a destroyer (as proven in the Russo-Japanese war, where destroyer duels were mostly incoclusive, despite hits on both sides).
Destroyers of WWII were armed with guns from 120mm and up to 150mm. The weapon of choice for sinking destroyers were the 6'' guns of the light cruisers, firing 110 lbs shells. Still, several full hits were required to disable a destroyer.
The 75mm would however be great vs PT boats, ammo dumps, fuel tanks, GV's (all but the PIV and Osty should be destroyed by a full hit of HE from any 75mm gun), not to mention vulching

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