Brilliant Uncirculated = MS-What?

The way I see it, there is no MS # equivalent to brilliant uncirculated. BU can describe a coin anywhere from MS-60 to MS-70 but I tend to see the term used more often with coins that would otherwise grade MS-60 to MS-62 since it is probably easier to sell these coins when they are described as brilliant uncirculated rather than something like baggy uncirculated. Neither of which, I think would be an inaccurate statement. The descriptive terms that I typically think of are:

Uncirculated= MS-60 to MS-62
Choice uncirculated= MS-63 to MS-64
Gem uncirculated= MS-65 to MS-66
Superb uncirculated= MS-67 to MS-69
Perfect uncirculated= MS-70

Just my Two Cents.