Updated 04 October 2007

USS New Hampshire B-25 in December 1910
An overall view showing the multiple calibers used on USN pre-dreadnoughts.  Forward and aft are 12" (30.5 cm) main gun turrets, the amidships turrets have 8" (20.3 cm) guns, there are 7" (17.8 cm) guns in the hull casemates and 3" (7.62 cm) guns in the superstructure casemates.
U.S. Naval Historical Center Photograph # NH 73979

7"/45 (17.8 cm) on Tractor Mount at Dahlgren Naval Proving Ground, Virginia

7"/45 (17.8 cm) "South Gun" now at Ft. Derussy at Pearl Harbor, Hawaii
Note projectile at right
Photograph copyrighted by Charles Bugajsky

7"/45 (17.8 cm) "North Gun" now at Ft. Derussy at Pearl Harbor, Hawaii
The "North" and "South" guns at this fort were originally from USS New Hampshire (B-25)
Photograph copyrighted by Charles Bugajsky

Another view of the 7"/45 (17.8 cm) "South Gun"
Photograph copyrighted by Charles Bugajsky

AP Projectiles