The seller is correct, they are a jacketed bullet, load them using jacketed data, using Gold Dot data would be fine also, and may be better considering the HB.
HBRN FMJ, is a jacketed bullet. The lead core is exposed at the base, but the rest of the projectile is jacketed.
There is also such thing as TP bullet, or Thick Plated, and they are capable of being loaded to full pressures intended for jacketed bullets also.
Then there are Gold Dots, which are in a class all there own. They still run with jacketed data, but they are a super thick plated bullet. Speer says they use a proprietary process of plating that bonds the core to the plating, the plating is way thicker than a typical plated bullet, and also thicker than a TP bullet.
GS