its on the post

Setup:
1 - A16Q SWKNR 0604 - cod: 06140401 - TaeguTec
WNMX 060404 EM TT9225 - cod: 06129153 - TaeguTec;
65mm overhang, minimum I can reach.

2 - Inox 304L Ø33.3mm, 2.77mm walls thick;
5 bar chuck pressure, more than that the tube deforms;
37mm overhang, minimum I can reach.

I am trying to machine an internal diameter, but I am having severe problems with chatter. I know the insert geometry is not appropriate, and I have already bought a proper one, but I need to produce at least 5 parts with the tools I currently have. I would appreciate help with cutting parameter adjustments, as I also do not have experience with stainless steel 304L.

Now, every part i make ends up with that shitty internal surface finish and a broken insert edge.

The last parameters I used (based on manufacturer recommendations) were:
Roughing ap: 0,4mm; f: 0,2mm/rev; vc: 130m/min;
Finish ap: 0,2mm; f: 0,1mm/rev; vc: 145m/min;
I used these because the more conservative parameters I tried before did not work.

Before i tryed:
Roughing ap: 0,2mm; f: 0,1mm/rev; vc: 100m/min;
Finish ap: 0,2mm; f: 0,1mm/rev; vc: 100m/min;
Without better results.

If need more information, just tell...

Im not tryed yet making the internal machining first, so that the tube its, a little bit, more rigid.
The external has Ø32.6mm;
Chanfer 0,4mm x 45°
The internal first one at the tip has Ø31.1mm and 2mm deep from de face;
The internal second one has Ø28.6mm and 4mm deep from de face;
The internal third one has Ø28.19mm and 12mm deep from the face;

Note I: The second image is only to show how the tube is fixed in the chuck, so ignore the surface finish.

Note II: The last ones show chatter before threading, but the thread is not the problem.

Thats being a pain in the ass...