Caliber

>>>BTW, can any naval types tell me what "caliber" refers to on the big
guns?
i.e. 5"/54  It's obvious that it's a 5in gun, but I don't know what the
54
refers to.<<<

The length of the barrel.  A 5"/54 would have a barrel length 54 times
its
bore (ie: 22 feet)

		    -M