If this was used for military purposes in WWII: 
Then your .380 should be.
Imagine a soldier who has just escaped from a prison camp behind enemy lines. Would a loaded .380 pistol he finds be of any military utility to him, or would be just pass it by, hoping for a real military gun to fall into his hands?
All functional weapons have military utility.
Perhaps, though the Second Amendment was not intended to protect any and all artifacts which might conceivably be used as weapons. If it were, the government would be unable to restrict anything.
For example, a bottle of alcohol, with a rag stuck in the end, can make a reasonably effective incendiary weapon. Does that mean efforts to tax alcohol or restrict its production are unconstitutional?