Every State sells BB guns, just not all locations within the state sell them.
US
No way to answer, since most states do not have registration for ordinary firearms. California would be a candidate for this, simply due to the large population.
Texas
The state that sells the most RVs is California. CA has always had a love affair with RVs. It is a very nature-oriented state.
By going to this guy who sells guns.
They made ammunition in most popular calibers.
florida
arizona
probably Florida since its the most tropical state
Hawaii
Florida