"I wonder if those big powder "cakes" (?) for the big deck guns on battle ships were Cordite?"
Yes. The British used Cordite for everything from handgun cartridges to the largest artillery.
It may have burned hotter than hell, but it was flexible.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.