Originally posted in the "I never knew that" thread
"The Mark 7 Naval Gun 16" 50 Calibre that was used on the Iowa class Battle ships was used against a surface ship only once in combat.
16 Feb 44, the USS Iowa fired a salvo at the Japanese Destroyer Nowaki at about 35,000 yards, but did not sink her. All other Mark 7 Shots were either training or land bombardment.
(Fischer, Brad D.; Jurens, W. J. (2006). "Fast Battleship Gunnery during World War II: A Gunnery Revolution, Part II".
Warship International. Vol. XLIII no. 1.)
During WWII, the accuracy of the Mk 7 rifle at range was pretty poor.
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At 30,000 yards, there was a 2.7% chance of hitting a broadside target and only 1.4% chance of hitting a end-on target.
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As modernized in the 1980s, each turret carried a DR-810 radar that measured the muzzle velocity of each gun, which made it easier to predict the velocity of succeeding shots. Together with the Mark 160 FCS and better propellant consistency, these improvements made these weapons into the most accurate battleship-caliber guns ever made. For example, during test shoots off Crete in 1987, fifteen shells were fired from 34,000 yards (31,900 m), five from the right gun of each turret. The pattern size was 220 yards (200 m), 0.64% of the total range. 14 out of the 15 landed within 250 yards (230 m) of the center of the pattern and 8 were within 150 yards (140 m). Shell-to-shell dispersion was 123 yards (112 m), 0.36% of total range
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http://www.navweaps.com/Weapons/WNUS_16-50_mk7.php
So even with the projectile tracking radar and our advanced FCS computers, we are still looking at no better than 150 yard accuracy. That's not so good when considering that even the HC (High capacity) Mark 14 projectile carried only a bursting charge of 153 pounds, in which half of that would be absorbed in fragmenting the projectile casing, leaves very little boom 150 yards away. The projectiles for the Mk 7 gun were still primarily big blocks of iron intended on slamming into the target assuming the target is big enough and does not move much.
There have been experimentation using sub-munitions, but they have not been too successful and too expensive
So let's look at the Mk 7 Gun operations.
Ammo and propellant is big and heavy. Normal battleship projectile load (and associated propellant) was about 130 rounds per gun barrel.
Which is probably enough considering the the life of the barrel was about 300 rounds and those barrels are not cheap nor easy to make.
Accuracy, even with today's electronics and the luxury of wasting a few rounds to get the trajectory right is still a best of 150 yards, with a 153 pound bursting charge. This means that you have to hit the target to really do any significant damage. Let's hope that our target is not much bigger than 200 yards and does not move. So what sort of targets would be appropriate?
Certainly not specific buildings. No, this is a weapon system for targeting small towns. Since there is a lack of large enemy fortifications, this would be a great terror weapon if you want to indiscriminately slaughter citizens, which is bad press. In Viet Nam, it was used a few times to create helicopter landing areas in the jungle, but there were better ways of doing that.
Shooting long distances with unguided munitions is a concept long dead.
Even old unguided rockets are better than a Mk 7 Rifle.
A SCUD-D (1980's technology), which is about as basic as you can get for TBM has a CEP of 50 meters, range of over 700,000 yards, explosive payload of about 2,000 pounds.
Pretty sure we have rockets and missiles that can do better than a SCUD-D
Battleships and the 16 inch rifle are, sadly, obsolete. Especially in today's OOTW environment where there are few stationary targets and a non-existent FEBA.
I would think that a better case could be made to reactivate (actually re-manufacture) Gato class WWII submarines. They would have more use than a WWII BB, in my opinion.
Battleships are cool, but then so are Trebuchets.
I would not want to fight a war with either of them.