bullet coper lodged in throat

[constructor]

While cleaning my barrel a copper ring came out of the chamber.
It looked like a copper piano wire coiled up. it was the dia of the bullet and had to come from the area between the end of the case and the leade or throat. It is rings of the bullets being shaved off by the leade. I was shooting 90gr TNTs and think the jacket could be so thin that it is deforming at ignition, possibly swelling into that area between the case and the leade.
Has anyone seen this before?
Should I have a new reamer made with a radius at this junction instead of a 45 degree angle?

 

[Klong]

It is hard to answer this from your decription. I have seen some small rings of copper from the bullet seating process. Are you using a VLD bullet style case mouth tool to put a bevel on the inside of the case mouth? If not this could be the source of the copper ring.

 

[Cheaha]

Yeah, it sounds like the case is shaving copper when the bullet is seated. A good VLD tool works wonders.