The Iron Age Directory, 1911 http://books.google.com/books?id=chtaAAAAYAAJ&pg=PA390&lpg Listed the following companies under “Steel, Gun Barrel” Edgar Allen & Co., Chicago, Ill. Bethlehem Steel Co., South Bethlehem, Pa. Carnegie Steel Co., Pittsburgh, Pa. Colonial Steel Co., Pittsburgh, Pa. Crucible Steel Co. of America, Pittsburgh, Pa Farist Steel Co., Bridgeport, Ct Wm. Jessop & Sons, Inc, 91 John St. New York C. Pardee Works, Perth Amboy, NJ Thomas Prosser & Son, 26 Platt St. NY Vanadium Alloys Steel Co., Latrobe, Pa West Leechburg Steel Co., Pittsburgh, Pa
In American Rifleman Nov. 1937, A.P Curtis stated in “Making Double Shotgun Barrels” that the American Gun Barrel Company of New Haven, Conn. made barrels for the U.S. market 1914-1921, but it could not compete with the duty free importation of tubes after Belgium recovered from WWI.