John Traveler is entirely correct regarding accuracy beyond 50 yards. The loading described is intended for close-range defensive use only, and for that purpose it is completely devastating in performance.
I have loaded and fired many hundreds of this type over the past 30-plus years, fired in 2" to 4" revolvers with no problems whatsoever. I would suggest that having the weight to the rear might just drive any potential obstruction out the bore, rather than leaving a forward portion lodged there.
I have also been present at an autopsy during which I was required to photograph the coroner's examination and recover physical evidence from the process. I cannot compare the results to anything attempted in ballistic gelatin or other media. The coroner was a very experienced pathologist, and described the results as the most devastating wound he had ever seen from a handgun fired into a human being's torso.
The HBWC design was developed to perform on the shuttle-cock principle (weight forward), with the added benefit of a thinly-skirted rear hollow-base that would expand into the rifling (much like the Minie bullet design).
In my experience, loading the HBWC with hollow-base forward works very well at close ranges, provided that the pressures and velocity are kept within standard velocity parameters.