Came across this thread and have often wondered the same thing regarding the 115 grain bullet. My curiosity was peaked when I started comparing one of my handloads with a Montana Gold 95 grain JHP to a Remington Ultimate Defense .380/ 102 Grain BJHP round. I found it interesting that while all the .380 bullets I can find are .355 in diameter the Remington measures .3485. This is measured just above the case mouth as I've not yet pulled the bullet but the case seems to indicate this measurement is true to the base of the bullet. Seems like a good way to keep pressures under control