Moly rings do need a smoother surface.

The grits can be confusing though. Thier ratings are differnt between the standard stones and the diamond type sunnen machine hones.

Also the new final finish these days is the Plateau brush or fine 400 grit standard stone for the moly.

If its as rough as you say the finish is probably not right.

Rule of thumb, 280- 300 grit for Moly, finished off with a plateau brush or 400 fine grit stone.

Or around a 550 grit diamond type stone finished off with a plateau brush.

As far as actually determining what finish you have, I dont know whats used to measure that. I do know its measured at a RA finish. Moly rings call for around 15 to 20 RA finish. mike