- Saginaw Steering Gear Division, General Motors Corporation, Saginaw, Michigan
- National Postal Meter Company, Rochester, New York
- Quality Hardware & Machine Corporation, Chicago, Illinois
- Underwood Elliot Fisher Company, Bridgeport, Connecticut
- Winchester Repeating Arms Company, New Haven, Connecticut
The "Sky Blue Arlington VA." marking is not a manufacturer's mark, but rather an inspection stamp used by the U.S. Ordnance Department at the Frankford Arsenal in Philadelphia, Pennsylvania. This stamp was used to indicate that the barrel had been inspected and passed quality control.
