I came across this site with some interesting history of US coastal guns through WWII. The main page is below, with an index if you scroll down some. The photos and quote below are on pages 11 & 12 of the virtual tour.
The site looks like it is no longer maintained, but there are still some good photos and history. Here are a few photos that caught my eye:
I love this view of the gun crew from the muzzle (I wonder if there was a photographer sitting way up there??):
Projectile table with 16" rounds:
And below may be my favorite part (quoted from the site above):
Photo: Test Damage to Armor of Japanese Ship from 16-inch Gun
(Private collection 1999, Washington Navy Yard)
Here is a message from Shawn Welch concerning this photo: This is a really interesting story related to me by FCCM (sw) Stephen Skelley (Navy’s Master Gunner for 16-inch). The plate in your photo is a face plate from a Yamato Class battleship turret (yard item) and is 26 inches thick. The plate was pierced by a 2,700 lbs projectile simulating an impact at about 30,000 yards of range. The test proved clearly that in a fight with an IOWA, the Yamato’s immunity zone was much smaller than originally thought, and would have been at a disadvantage.
The neat part about the test is there is another plate at the Navy yard that is connected to this test. That plate is the roof of Turret 1 from the USS South Dakota. During the Battle of Santa Cruz in 1942, a Japanese dive bomber scored a direct hit on the roof of turret #1. The crew of the turret did not know what happened (and continued normal duties). The center gun of Turret #2 was right over the detonation point and the rifling was badly scared. When the gun was removed during the repairs required for battle damage sustained by USS South Dakota after the night action of November 1942 (where the battleship USS Washington sunk the Japanese Battleship Karishima), the gun was returned to the factory and relined. It subsequently was sent to Dahlgren to be used as a test weapon, and fired the rounds that tested the Japanese Armor plates.
There are also pages on the site with 12" mortars and 6" rapid fire guns. Some of the later pages no longer load the photos, but the text is still there.