This shell has a metal cap that has impressed into top the words
REMOVE THIS CAP BEFORE USE
12 GUAGE BUT WHY THE CAP?
Any clues? my guess is for morter’ but other morter cartridges i have seen do not have a cap. TERRY.
Terry–I’m not positive, but I think this is a starter cartridge for large diesel motors like in large tractors.
I think that your round is for some civilian purpose too
Anyway I have a mortar starter cartridge made by Federal for the 120 mm mortar that has the same brass cup on the top
I HAD THE SAME THOUGHT ABOUT A STARTER CARTRIDGE BUT THE CAP PUT ME OFF AS I HAVE HAD STARTER CARTRIDGES WITHOUT THE CAPS.
BUT IT CERTAINLY COULD BE AS I DON’T COLLECT SHOTGUN CARTRIDGES BUT HAVE HAD AND HANDLED MANY AND ITS THE FIRST CAPPED CARTRIDGE I HAVE SEEN.
POSTED PICTURE IN CASE IT WAS SOMETHING MORE INTERESTING.
SOME RESEARCH SUGGESTS A STARTER CARTRIDGE, ALLTHOUGH THE PICTURES OF STARTER CARTRIDGES HAD NO CAPS IT WAS POINTED OUT THAT POWDER LEEKED FROM CRIMPED CARTRIDGES SO THAT WOULD EXPLAIN THE NEED FOR THE CAP BEING USED BY COMMERCIAL SUPPLIERS
Most probably a Marshall Tractor Starter Cartridge, made by Eley Brothers
These tractors were fitted with a heavy Flywheel, were Diesel fuelled, and needed a “Kick start” back in the pre-WW I era when these tractors were introduced. The principle of Cartridge starting was used in a lot of single and twin cylinder diesels, to get the first compression going on a heated Glow-Plug. After the Engine started turning over ( thanks to the large Flywheel,) the compression heat supplied the ignition of the fuel (Full Diesel principle).
The Cartridge Starter system was also used in some Propeller and Turbo- Jet Engines as well; ( before the Ground unit electric starter was introduced.) Canberra Bombers ( Brit. Version of US B57) used a large Aluminium Starter Ctg. ( about 4 gauge size) made by Olin Corp…I remember seeing bins of fired ones at a Military Scrap Disposal Auction back in the 1970s.
Since the Marshall Starter Cartridge was originally Black Powder, the crimps sometimes “dribbled” Powder, so a cap was supplied. Later versions had either a Lacquered crimp, or were completely sealed by an extra wad.
The British Canberra used a brass cased started cartridge of around 75mm calibre as far as I know. These are extremely common here in the UK, and are often sold as artillery cartridge cases.
The use of cartridge starting was a characteristic of the Rolls Royce Avon engine used in the Canberra bomber. Jack
Quite correct, the Canberra used a large brass case ( 57 mm or “6 Pounder” size).
It was some other Engine (RAAF) which used the ?4 gauge? short shell.