Tumbler Model B High Speed in 220V variation

[ANDY T]

Rotary Tumbler Model B High Speed in 220V variation

Hi
I have just got the above tumbler i have a question for anyone that can help.

I have just done my first tumble with some 6mmbr brass a i have found that the brass has come out with a very sharp lip about 1mm down from the top of the neck.

I don't know if the tumbler has done this or weather it was like this before it went in to be tumbled, have you found this happening to bass you have just tumble using a rotary tumbler???

Regards
Andy