I had thought that I had private loans back in the day. Been a long time since I paid all of mine off, though, so I can't remember who they were through. (And, I fully grant that, even if I was private loans, 8% is still a non-zero number...)

Before federal loans were all direct (Ford loans), there were federal loans issued through third-party lenders (Stafford loans) that otherwise worked the same way with the same kinds of loans (subsidized, unsubsidized, PLUS; for a while, both Stafford and Ford were offered at the same time, with identical terms.) These are collectively “federal” loans (and there are still balances on loans originated as Stafford loans) distinct from “private” loans.

I remember I maxed out my Stafford allocation, and then also had to get extra loans to cover my last year. Memory being what it is, I wouldn't be shocked if I am misremembering some.

Regardless, I got them all payed off; and still have a massive distaste at how most discourse over this goes.