Most of the stuff you mention is illegal in most places. Clearly not relevant to the conversation.
Do you have proof of those rounds being illegal in "most places"? Do you really think that dealer would sell those rounds if they were? The locations where the ammo can't be sold is listed with every variety mentioned. Do you REALLY think they sell ammo to places it is illegal to own it? Maybe by "most places" you mean the city where you live. None of that stuff is illegal where I live.
As far as being relevant to the conversation I responded to a point made that an AR was more versatile which is clearly not true. Even with ordinary loads available everywhere the shotgun is far more versatile. And some of those specialty loads could very much be a part of HD if a person wanted to use them.