Original U.S. Vietnam War Era HGU-26/P Flight Helmet with Dual Visor and Oxygen Mask Antique Colts 4mm Vetterli centrefire cartridge

4mm Vetterli centrefire cartridge

"it was the first original breech-loading gun in the U

The top of the octagon barrel is still stamped:

BURNSIDE PATENT

particularly large caliber machine gun cartridges

Original U.S. Vietnam War Era HGU-26/P Flight Helmet with Dual Visor and Oxygen Mask Antique Colts 4mm Vetterli centrefire cartridgeOriginal Item: One of a kind. The HGU 26 P request for nomenclature is dated Jan 14, 1970 and is based on the HGU 22 P Helmet Shell. There is no military specification detailing exactly what goes into an HGU 26 P but until the appearance of the single visor HGU 26 P both USAF and manufacturer information was consistent in describing the HGU 26 P as an HGU 22 P helmet shell with a PRU 36 P side actuated double visor. Sierra Corp and Gentex Inc sold