It may go back even further, but the term was used during prohibition, and popularized by the old James Cagney movies. It MAY have been a shortening of "Gattling gun", but it is unlikely that any 1930s mobster was actually using a weapon from the late 1800s.
Chrome Gat
If you mean gay, no. If not, I have no idea what gat is!
Gat Kirwani was created in 1968.
Kiryat Gat was created in 1972.
Gat Rimon was created in 1926.
Gat Perich was created in 1996.
Eliahu Gat was born in 1919.
Eliahu Gat died in 1987.
Azar Gat was born in 1959.
johney gat 6'6 to 7'0.
Kiryat Gat's population is 47,400.
Gat Stires died on 1933-06-13.