Excellent. There's no reason defensive gun buyers should be demographically different from the general population. It's understandable that gun sales for hunting or other activities might show differences, but we all have the same personal security needs. Side note: I'm one of the people here with a large collection of firearms. One thing to realize when you see the statistic that the US has more firearms than people…
Your standard of combat is obscenely high. Any weapon that can kill an animal can be used quite well against humans in defense. Would they be standard issue arms for a modern army? Irrelevant.
Among my collection is a 100-year-old 16ga. H&R single-barrel shotgun passed down through four generations. It hasn't been fired in decades, and hasn't seen an armorer in longer than that. Not only is there no semi-auto, there is no magazine at all, and even if you'd be willing to go to war with something that needed to be manually reloaded after every shot, I am not altogether convinced the breach wouldn't explode upon firing.