During the late 1960's the Hughes Tool Company came up with a new idea in cartridge and breech design. The idea was a flat telescoped cartridge and a breech which consisted of a slot milled through a barrel (the breech was plugged). The cartridge was inserted and a pressure sleeve slid over the barrel. The sleeve withstood the pressure. No breechblock or lock was required.
Plastic cases were normally used and it did not matter if they split because the chamber was sealed by conventional piston rings between the barrel and sleeve.
The round was tried in most calibres between 5.56 and 40mm.
The photographs show 4 different 30mm rounds (which used standard GAU 8 projectiles) and a 12.7 round (photographed next to a conventional 12.9 X 99 round for scale). All INERT.
Dave.
Plastic cases were normally used and it did not matter if they split because the chamber was sealed by conventional piston rings between the barrel and sleeve.
The round was tried in most calibres between 5.56 and 40mm.
The photographs show 4 different 30mm rounds (which used standard GAU 8 projectiles) and a 12.7 round (photographed next to a conventional 12.9 X 99 round for scale). All INERT.
Dave.