Total weight of an Iowa broadside:24,300lbs x 2 salvos = 48,600lbs
Total weight of Bismark broadside: 14,112lbs x 3 salvos = 42,336 lbs.The Iowa, with a longer firing cycle, is still putting more ordance on target than the Bismark. Look at the technical history books, the USA had the best fire control radar around. The Bismarck would have some good damage before she could get into her gun's range, remember, the Iowas guns have farther
range. As far as armor goes, the Bismark doesn't hold a candle to the Iowas.
Iowas armor belt was interior of 4 compartments, 2 void and 2 liquid filled, the outer hull was made up of STS plating, which only the USA had the luxury to afford. The STS plate, proved to decap a majority of AP rounds, thus denying them penetration. On top of that, actually behind this setup , was a 12.1" armor belt inclined at 19 degrees from vertical, this was equal to a 17" vertical belt. The deck armor was a total of 6" with STS plate protection, the bulkheads were 11". The barbettes were
17.3" and the conning tower was 17.5".The main turret armor was 17". And it was shown, that the farther the distance, the greater the vertical penetraion the 16/50's had. Add to that, the Armor the USA produced was the best in the world, mainly
because we could afford it.
The Bismark had a 12.6 " vertical ,exterior armor belt with only 2 compartments inboard of that. Her decks were 4.7",the bulkheads were 8.7", barbettes were 13.4",the conning tower was 13.8" and the main turret armor was 14.2". Start reading some books with technical information in addition to history, and maybe you'll see the light. The Bismark did put up a good fight, she fought well, I won't argue that, but to say she would have beat the Iowa, isn't very realistic, if you would compare the
specifications and qualities of each ship design.
Saying the 15" guns were superior to the 16" is false. The 15" had a higher firng rate and the Germans had good optics.But again, with superior fire control radar and longer gun range, the Iowa could blindfire at the Bismark before the Bismark could even get into range to use her optics or guns ! Plus, the 16"/50 shell was heavier and had far more armor penetration than the 15" shell.
Another thing, yes, I have heard the Germans scuttled the Bismark. But what does that matter? Her topside was a twisted, flaming wreck, everything was blasted away. A floating hull full of holes isn't very threatening.
One of my sources, (not my only source), but a good one is here:
http://www.combinedfleet.com/baddest.htm
This guys has done a lot work, he has pitted several battleships against each other using armor/gun calculations.