Actually they are not. If you hold a 380 tip to tip with a 9mm the 380 is noticeable smaller.I'm not convinced the sorter will separate the 9mm from the 380 since they are the same diameter just a couple thousandths difference in length. I too stand them up and look at the length. Also I can eye them and get most of the 380 out when dumping them out of the tumbler. Not all though.
This is what happens when you mix young children and reloading equipment.for fun you can put 380 brass upside down in a 40s&w and load only with a primer and shoot them at cans in your garage !!! they don't ricochet like a bullet and if they come back at ya it don't sting at all yes eye protection is a requirement