China. At first they made fire works and that's biw the gun was made
The gun was made in Belgium; by FN (Fabrique Nationale) in Liège.
The first nail gun was planned in New York by 3 WW2 vets working on construction projects. They planned it in 1954 as the Port-a-Matic Nail Gun, and later sold the design to Bostitch.
China
The "First model Rifle" was made in 1923. The first gun was around 1947.
Dozens of countries
Are you asking about the first Gun or Rifle? The first gun was made in 1935 it was part of the 100 series (100, 122, 177) the first rifle was made in 1899 (the St louis)
The first was the gatling gun invented in 1862
Countries. It was made in Israel and in the US.
China
China
Britain