"projections about" is correct and usable in written English.
You could use it in sentences such as, "The report included projections about the company's future growth."
For California, do you have any conclusions or projections about right to carry and the lobbying here?
PROJECTIONS about Buster Keaton's birthday.
Federal government budget projections about to be released.
PROJECTIONS about actor Linus Roache, who is appearing in "Priest".
David: I'm very skeptical of demographic projections about American politics.
My projections about increasing global temperature have been proved true.
Results show that many projections about the impact of the EPC have fallen short.
Therefore, any uncertainties in the projections about future climate directly translate to uncertainties in future runoff.
e360: Do you have any projections about when you would have one?
However, we can make projections about how coverage will change in the coming years.
He said states and municipalities finally started using more conservative projections about a year ago.
