I ended up hitting about 82-85% with my corona mill on its inagural spin. I was planning on 75% for my Mild, so it ended up being about 1.044OG instead of 1.040OG. I topped my pot with as much water as it could hold, but I think I only got it down to 1.042OG. Which is probably good that I added a bit more volume, and the slightly higher OG.
Because I accidently did my hop additions pre-boil, at 60 minutes, at 30 minutes and at flame out. I had intended to do 60 minute, 30 minute, 10 minute and flame out. But I did pre-boil and then forgot that I needed to wait till 30 minutes. So my IBU went from around 32-34IBU up to more like 45-48IBU. Kind of pushing an English light IPA or something (too dark for that though). Fingers crossed.