Here is a bit of cartridge curiosa, the 7mm Broadway Trust.
This was developed by Sir Dennis Burney of ICI, and the Broadway Trust Comapny was a cover jointly owned by Sir Dennis, ICI and the Ministry of Supply. The cartridge was designed to fire in a recoiless rifle and used extremely long projectiles. There were a number of recoiless weapon developments ranging from small arms to artillery. The company existed from October 1943 to 1948.
Attached are pictures of two types of case, the unfired bullets and some fired and sectioned bullets from my collection.