@mrobisr no worries, I have 3 or 4 on order for the sizes I need, that had a nice solid base f l a n g e wide enough for me to grind.
Went with 10mm for 16 to 18mm casings
12mm for 19mm casings,
12.7mm i.e 0.5in for 21mm casings,
and 19mm I think. Maybe 1 is a real 2in base, rest will be ground.