Here are some pictures of a rather unusual cartridge that I found at a cartridge meeting here in the UK. I initially thought that it was an experimental dummy cartridge of some sort but as far as I can make out it’s actually an Olympic Match cartridge. The primer assembly is easily unscrewed and removed, the cartridge is loaded with propellant, a primer is inserted and the cartridge is reassembled to fire. The theory is that the ignition takes place at the end of the primer vent tube and this was supposed to give an improved ignition. Not successful because too much powder space was taken up by the brass primer assembly. The case is of brass and the bullet appears to be a Mk 7. The cartridge weighs 437.6gns.
There are no markings on it and I’ve no idea who made it.