United States is considered to be a well-armed country. It has an army that is well equipped, but also many regular citizens have weapons. There is a large portion of population that agrees that many weapons are cool. That is why there are so many movies where the protagonists and antagonists use weapons. There are also many TV shows where the main characters use a weapon of some kind. I think that the majority of people got used to seeing various types of weapons. Those who own a shotgun might need some kind of mossberg 500 shotgun accessories. These days there are many weapons and accessories on the market.