This cartridge is an experimental one developed by Frank Marquardt over the period 1946-1950 for the American Navy Airforce.
The brass case has no rim or groove
The cartridges were "shot" into the chamber from a container with an electric primer in a much reduced head.
The driving band was specially designed driving band to absorb the shock of firing into the chamber and to prevent the case from buckling.
They are found with aluminium and brass cases.
The containers are linked with springwire links.
The photographs show the round inside the aluminium container and also separate, the case headstamp, the container head (empty primer socket) and the links.
All INERT and safe etc.
Dave.
The brass case has no rim or groove
The cartridges were "shot" into the chamber from a container with an electric primer in a much reduced head.
The driving band was specially designed driving band to absorb the shock of firing into the chamber and to prevent the case from buckling.
They are found with aluminium and brass cases.
The containers are linked with springwire links.
The photographs show the round inside the aluminium container and also separate, the case headstamp, the container head (empty primer socket) and the links.
All INERT and safe etc.
Dave.