Leigh Youdale
Well-known
My thought is this was probably under-exposed and over-developed, resulting in what appears to be very high contrast.
I'd agree with Chris. The overdevelopment will block up the shadows and accentuate the grain. I have no knowledge of HC-110, but I do know that, for me, Rodinal 1+50 produces an undesirable grain in HP5+ even when the exposure is correct and I prefer to use DD-X or ID-11 (D76) with that film.