They have an effect on the world.
In much the same way as hammers, autos, home appliances, drug companies, etc.. They are an industry that employes people and pay taxes.
it affected it by gas.
Yes. About one third of us that are adults do own guns. Legally.
18 for long guns 21 for hand guns
Despite belief to the contrary, in MOST of the US, there is no requirement to register ordinary guns.
Yes.
Trade
Yes
They use a lot of guns given them by the US BATF.
No one record. Estimates are about 310 million guns.
Like most of the US, there is no registration of guns in Texas.
what was the effect of machine guns, tanks, poison gas, and airplanes used in the battles along the western front