What are Fender 8250 taperwounds?

[michael_t]

I was surprised too, since the reason buying them was me thinking they're round core. But they weren't terribly stiff for hex core in these gauges. I might buy them in the future again since they're reasonably priced and sound fine. I like them more than D'Addario EXL although I know D'Addario makes them.

D'Addario has never offered round-core strings for their own brand. I wouldn't be surprised if they decided it wasn't worth their trouble to have to deal with round cores just for one Fender-branded set. They might have thought they could achieve the same flexibility and suppleness by using a smaller hex core the way they did with the now-discontinued FlexSteels.