And carrying concealed, which is allowed in 42 states, plus many less urban counties of California and New York, and cities in Massachusetts. That's something like (from memory) 72% of the US population, as long as you're an adult 18-21 and haven't committed a felony etc. States with concealed carry right now have issued licenses to 5-10% of the age eligible population, well more than 12 million by now, plus 10 states don't require a license, with Missouri likely to join them by the end of the year.

Guns also become a more important means of self-defense the physically weaker the person, so the need, and observed statistics are weighted towards older people, and the US is rapidly graying with the demographic Baby Boom.

Hunting is also a popular pastime in the US, and is in fact a critical resource in controlling various prey populations after we wiped out the apex predators that used to keep them in check. As it is, deer are now the most deadly animals in the US due to collisions with cars.