Thanks everyone.
I just removed the spring and filed off the burr.
Yes, reinstallation was a PITA but I got it back in.
Now everything is smooth as silk.
BTW, I use Li-Ion cells, so the continual scoring could have been a problem.
Ahhh ok I understand now. I've only used primaries in my stuff.
Good to hear it came through the operation ok.
Hmm what could you call it?.... A Spingdectomy?