Given the short service duration, it's unlikely that the MKIII Manstopper did a lot of manstopping, but I am curious about what record it may have generated. I tend to think that being 218 grains of hollow point/hollow base wadcutter, effective penetration may have been compromised and that its reputation may be a bit inflated by the mists of time. As the Ballistic Scot says, "mythic history". Unfortunately, it just about has to be a swaged bullet, so testing is going to be beyond my financial and technical means.
The flat nose/hollow base MK IV and V's could be a possibility. We started a group buy discussion on them over at NOE a long while back, but didn't manage to generate much of a feeding frenzy.
Tumbling vs. not tumbling. . .I'm curious to find out, but I hypothesize that at 600-700 fps, we aren't going to see much that is consistent or dramatic. These are not, after all, base-heavy 5.56 NATO bullets striking at SR-71 speeds. On this topic, however, does anyone know what the regulation British bullet alloys were for these things? If I'm gonna test the Queen's Bullet, I should probably use the Queens Metal.