I know it's an old thread but, I had the same problem using the lee die set and 90gr xtp bullets. All other bullets I used worked fine until I tried the xtp. I didn't think .001 difference was going to be an issue and it mentioned nothing in my Honady reloading book about any extra steps or special tools to load the 90gr xtp in the 380 acp. It's definitely the lee die. I bought a Hornady die set and have no issues at all now. I measured the ID of lee die and it is .3675, I measured the Hornady die and it is .3645. I did notice though that the Hornady sizing die leaves the case looking dull. Didn't have that issue with the lee but I'd much rather have a tight bullet then a shiny case. My OCD is in full effect over it so, I'll just run them through the polisher after sizing.
