The only reason to have a constitutional protection for guns is that they are weapons that can be used to protect the state from foreign and domestic enemies, protect oneself and those near to you and resist tyranny.
As simple tools or instruments of recreation, they are too dangerous to have around. You have no right to bowl in the Constitution.
In the UK and Australia, the tool and sports argument led to draconian gun bans as they were not convincing given some mass shootings. It is only the use of guns as weapons that is the defense against taking them away. Guns for sport and hunting could easily be locked up and checked out for a day at the range or to shoot a ducky.
As far as the previous argument on sexual images, we have demonstrated that Doug doesn't really understand freedom and is basically just one of the crowd that wants a gun and wants to be an authoritarian on most social liberties. That disconnect is a major weakness of the gun world. Folks who bellow for gun rights in one breath and then wants the Fed or the state or local level to police the activity of consenting adults are hypocritical - if they bother to apply logical thought processes over prejudices.