Gary, I believe the 44 referenced the frame size of the guns the rounds were to be used in. i.e. they were to be used in the N Frame guns not the K Frame. The N Frame was developed for the .44 caliber cartridges. Hence the .38 stood for the actual caliber of the gun and .44 referenced that the round was to be used larger frame guns.

I'm sure someone will correct me if i'm wrong or give a more concise answer...