Personally, I would just get some .380 brass and that way you won't have to worry about mixups. You would not need a whole lot, and it is not that expensive. I bought about 500 pieces about 8 years ago, and I am still using them. Also, I believe that the base is just a tad smaller than the 9x19, but I would measure to check that.
“The very powerful and the very stupid have one thing in common. Instead of altering their views to fit the facts, they alter the facts to fit their views...which can be very uncomfortable if you happen to be one of the facts that needs altering.” The Doctor