The message
from Chris Bacon contains these words:

I can't see a chamfer on the pipe, it looks as if it's just been
sawn off straight. The gunk at the top could be - erm - well -
just some sort of gunk, I suppose. The OP will find out sometime.

I reckon the gunk at the top is a chamfer.

--
Skipweasel
Pay no attention to that man behind the curtain.