The issue does not happen with factory loads. I too thought is was the extractor, hence the deep clean of the gun.
I decap and resize on a RCBS press. This way if a 380 is in the mix, I can sort it out.
The other steps of reloading are done on a Lee Progressive.
I have measured a handful of spent brass, before decaping / resizing and all have fell within spec. 0.744 - 0.754.