A soda gun or bar gun is a device used by bars to serve various types of carbonated and non-carbonated drinks. A soda gun has the ability to serve any beverage that is some combination of syrup, water and carbon dioxide. This includes soft drinks, iced tea, carbonated water, and plain water. When served from a soda gun, these are often known as fountain drinks.

Can we draw the following conclusion?
It is called a soda gun in some countries while it is called a bar gun or some other countries.
It's impossible to say