[null and void]

16"/50 caliber Mark 7?

Shouldn't that be:

16"/50 calibers Mark 7

As in the barrel length is 50 times the shell diameter/caliber?

[LonePalm]

Uh, no. BuOrd officially designated it as the 16"/50 caliber Mark 7. In this case the Mark 7 referred to the gun barrel.

Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)